what it feels like to have a fully developed brain

being 25 for a month, ins and outs in the half of 2025, dispatches from the fully formed mind

Let me be clear first: I didn’t wake up on my 25th birthday last month with an urge to budget or stretch. There was no celestial chime. If anything, I wrote a piece on my Medium saying how prepared I was to face this age, no matter how different it is from the scenario I’ve been writing in my head my whole life.

But now that I’ve spent a little over a month being 25, there are a few things I’d like to clarify – and maybe offer a light update on what it’s like to be in this particular age bracket. The age where, according to both neuroscience and the internet, your frontal lobe is supposedly fully developed. The age of finally ‘logging in’ to your prefrontal cortex.

I didn’t expect to feel any different, but lately there’s been this reorientation in how I move through things. I take a second longer before agreeing to something. I recover faster from things that would’ve lingered before. I’m not necessarily making better choices (at least this month), but I can tell I’m considering them more carefully. It’s subtle, but noticeable. And apparently, that tracks.

Source: Random tweet on X

Which brings us here. For the past few years, I’ve often come across this random fact that by 25, your brain – specifically the frontal lobe – is finally done developing. It’s the part responsible for all the so-called adult things: decision-making, long-term planning, self-control, emotional regulation. Basically, the part of your brain that tells you not to buy a plane ticket just because you’re sad on a Tuesday. The same part that starts to question whether saying yes to everything laid out in front of you is the same thing as choosing it.

In simple terms, this development happens because your brain is still pruning and strengthening neural connections well into your twenties. The prefrontal cortex – the area just behind your forehead – is one of the last parts to fully mature. It’s like the brain’s management office: it balances impulse with reason, wants with consequences. By 25, most people have a stronger internal filter. You become better at recognizing patterns, anticipating outcomes, and thinking beyond your current mood. Which means: less acting on emotion, more pause to think, more doing things that are aligned with a longer-term sense of self.

That’s why after 25, the highs aren’t as dizzying – but the lows also don’t knock you out as easily. You feel less dragged around by every little thing, but also slightly more aware of what you’re letting into your life in the first place. That said, this piece won’t go all scientific on you. I’m more interested in what it feels like to live inside that supposedly fully developed brain. What’s changed, what hasn’t, and what still catches me off guard.

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I think most people around me would agree that this year’s been moving at an absurd pace. In just a blink we’re halfway through 2025 already and frankly I don’t remember much of how we got here. I do remember being tired all the time, though.

There’s been a lot packed into these first six months. Projects, transitions, some emotional housekeeping. But also, surprisingly, a lot of rest. More than I’ve allowed myself in previous years. Maybe that’s why it feels blurrier in memory. Not because it was empty, but because the pace wasn’t punishing.

And so this midpoint (plus one month of living as 25-year-old!) feels like a good moment to take stock. A soft inventory of what’s been working and what’s quietly expired. A loose, personal list of what I’d like to bring with me into the second half of the year – and what I’d rather not:

INS - What I’m keeping (and hoping to keep showing up for)

1. Family gatherings

I used to think I wasn’t particularly close with my family – at least not in the way some of my friends are. But lately, I’ve realized it might actually be the opposite. My family has always been laid-back with me, surprisingly open to most of what I do. Ever since I was a kid, they’ve known who I was dating, what I was fighting about, and what the follow-up plan was. I’ve always been kinda an open book. This year, I want more of that. We’ve been gathering more frequently, and it feels good. My grandmother passed away a few months ago, and it reminded us – painfully, clearly – that time spent with family is never wasted, and it’s never really enough.

2. Time with friends

I joke a lot about being too old to hang out – that my social battery sometimes can’t take it anymore, or that I’m in a different phase now. But sometimes I wonder if that’s just a polite excuse I’ve built to protect other priorities.

The truth is, I can make time for my friends. I just haven’t always wanted to give up what I think is more valuable or productive. Still, the regret shows up afterward. I wish I’d gone to that trivia night. I wish I’d said yes to karaoke. I wish I’d bought the tickets for that musicals. And I don’t want to keep wishing after the fact. Sometimes the hangout is the thing worth wasting time on.

3. The done-is-better-than-perfect mentality

I’m done done overthinking everything I make. Not everything needs to be perfect, especially when it’s something I’m creating myself. Lately I’ve been trying a one-sitting writing method, and it’s been working. Most of the pieces I’ve published here the past few months were written in a single go. People sometimes comment on how serious I look. How it reads like I’m writing as if I’m running out of time. My usual response is: “I’m a writer. This is the thing that I do.” What I don’t always say but I’ve been hearing louder in my head lately: I’d like for that to be respected, too. No matter who you are.

4. Better disciplined with my time

In my schedule, in my workouts, in how I move through the day. I used to tell myself there was always something more urgent, more deserving of attention. But most of the time, that wasn’t true. I’ve been more disciplined lately, and it feels like something is finally clicking.

I’m still impulsive and spontaneous in a lot of ways, but I’ve also learned to enjoy structure. I like when my days feel efficient and intentional – like my life is something I actually want to live through, not just keep up with. I’ve become stricter with the plans I make, and that means people or tasks can’t just slip into my time whenever they feel like it. If someone cares about me, they’ll understand that. They’ll make room without making demands.

5. A more strategic work mindset

This year, I’ve taken on more projects – and they’ve come in a range I didn’t expect. That alone feels like a step forward in my career, not just in quantity but in complexity.

And with that has come the realization that I want to work with more strategy. Not just doing what’s familiar. Not just saying yes to what I already know how to do. But actually learning how to make decisions that support a larger direction – one that makes room for growth, both for myself and for the people around me. I’ve been reaching out to mentors more, asking better questions, letting myself be new at things again. It’s been challenging in the best way, and I want to keep moving like that: a little more intentional, a little more aware of where this is all leading.

OUTS - What I’m letting go of (or at least trying to)

1. Overexplaining myself

I don’t know when it started – probably sometime between trying to be understood and trying to be likeable – but I’ve noticed how often I explain my choices, even when no one’s asking. The book I’m reading, the film I’m watching, a project I’m working on, why I left somewhere early, and the list goes on and on and on. I feel this weird need to soften the edges. Lately I’ve been practicing just saying what I mean and leaving it there. I don’t need to rehearse justifications for things I already stand by, and I’m learning to let my choices speak for themselves.

2. Entertaining what doesn’t excite me

There are people, places, and plans I used to say yes to because I didn’t want to seem difficult. Saying yes out of habit. Or because I thought that was what adults do: show up anyway. I told myself it was flexibility, that showing up was better than nothing. But more often than not, it left me feeling distant from my own life. These days, I’m more okay with passing on things that don’t spark anything in me. I don’t want to keep filling my time with placeholders.

3. Working just to stay busy

There was a phase when I treated a packed calendar like a sign of progress. The more things I was juggling, the more it looked like I was going somewhere – even if I didn’t know where that was. It made me feel productive, needed, useful. But busy doesn’t always mean aligned. I am now more interested in choosing work that feels grounded. Building toward something – not just fill the hours. Growth doesn’t always come from being constantly in motion. Sometimes it comes from knowing when to stop.

4. (Tolerating people who treat me like) a version of myself I’ve already outgrown

Some people still respond to a version of me that doesn’t exist anymore. I know I can’t expect everyone to immediately forget who I used to be or fully grasp who I am now – but sometimes, it’s clear they’re choosing to hold on to that older version, because it’s the one that feels most convenient to them. I’m not saying what they do is all wrong, or that they’re bad people. But I’m letting go of the part of me who stayed quiet when I should’ve spoken, who avoided conflict by doing things that ended up hurting more, who moved through the world like nothing was political – as if passivity was harmless, and staying neutral was somehow wise. I no longer feel the need to be understood in those rooms. I’m learning to walk away when being myself feels like too much. That’s not mine to carry anymore.

5. Romanticizing the wrong kind of struggle

I used to think being exhausted all the time meant I was doing something right. That showing up while burned out was admirable. That saying yes through gritted teeth made me strong. But not all struggle is meaningful. Not every hard thing is worth holding on to. I’ve realized there are certain kinds of difficulties I no longer want to build a life around – no matter how poetic it might seem from far away. I still believe in effort, in care, in trying. But now I’m more careful about where I place it. Some battles don’t need to be fought. Some stories don't need to be played out just to prove a point. I’m choosing peace in places I used to choose persistence.

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So after laying out these ins and outs, I think I can safely say that my frontal lobe is, in fact, fully developed. It’s here. It has arrived. Took its sweet time, but it made it.

It’s only been a little over a month, I know – but at the very least, I’m trying. Based on this list alone, I think mine is finally starting to participate in the process. Not in meetings or big life declarations (yet), but in small things: what I say yes to, what I quietly release, what I no longer argue with myself about. There’s less panic. Less noise.

Now all that’s left is to follow through, one action plan at a time. Some will be easy. Some will take a few tries. Others might require me to accept things I’ve spent years trying to work around. Like the fact that some paths are just not meant to merge, no matter how hard you want them to. Some situations are romantic in theory but exhausting in practice. Some kinds of struggle aren’t signs of strength; they’re just slow forms of self-betrayal.

And even when I forget all that, I know I’ll remember again – because I have people around me who remind me, directly or not, what it looks like to live with a sense of direction. My support system has never needed to be loud to be grounding. It could be a small gesture, a conversation, seeing someone else choose themselves over and over again and thinking, yeah, that looks like something I could try too.

So if this is what it feels like to have a fully developed brain, then I’ll take it. I’m still me, but steadier. Slightly more discerning. A little softer in ways that matter. And if I ever forget, at least now there’s a part of me that knows how to remind the rest.

Everything Everywhere All at Once (2022), dir. Daniel Scheinert, Daniel Kwan