There's a moment, maybe forty minutes into a hard sparring session, when someone heavier than you settles into side control and your lungs are on fire and every part of your brain is screaming at you to push, just shove them off, and you know from a hundred previous mornings that pushing is the one thing that'll get you choked. So you breathe instead. You make yourself small. You wait for them to shift their weight, and when they do, you go.

Most days I don't get out. But I'm getting out more than I did in January.

I've been training six hours a day, six days a week, for about four months now. People assume that must feel like a holiday because I'm not "working", and I laugh, because I've never been this tired in my life, not even in the worst launch weeks. It's a different kind of tired though. At the end of a startup day my head would be buzzing and my body would feel like it had been left in a chair. Now it's the opposite. My body's wrecked, and my head is completely quiet.

I've been trying to work out what the mat is teaching me that startups didn't. There's a lot of overlap, obviously. Both reward grit, both punish ego, both involve a lot of losing before you win anything. But a few things are genuinely new, and I want to write them down while they're fresh.

The first is that you can't talk your way out of anything. I'm good in a room. I'm animated, I can tell a story, I can make a rough product sound like it's going to change the world (occasionally it did). None of that works on a mat. Nobody cares how well you explain your guard. Either the sweep works or it doesn't, and you find out in about two seconds. That feedback loop is brutal and honest and I think I needed it more than I knew.

The second is about my body as a tool. For most of my adult life my body was the thing that carried my brain to meetings. I'd think of it when it complained and ignore it the rest of the time. Jiu-jitsu doesn't let you do that. You start to notice where your weight is, which hip is loaded, how your breathing changes when you panic, how a tiny adjustment of your elbow makes the difference between being stuck and being free. It's like discovering you've owned a very sophisticated instrument your whole life and only ever used it as a doorstop.

The third is what excellence actually looks like up close. In startups, excellence is fuzzy. You can have a great quarter because the market is great, and a bad one because it isn't, and it's hard to tell how much of it was you. On the mat there's no bull market. There are people at my academy who are simply, unarguably better than me, and the gap between us is made of thousands of hours of drilling the same small movements until they stop being movements and start being reflexes. There's no shortcut and no hype. Just reps.

I find that incredibly comforting, strangely. For the first time in years I know exactly what I need to do to get better. Show up. Drill. Roll. Tap. Ask a question. Go home, eat, sleep. Come back.

The fourth thing is humility, and it's arrived in large doses. I've spent years being the person with the answers. Now I spend most of my day being folded into shapes I didn't know a human could make, by people who are younger and lighter than me and who are very polite about it. My ego has been handed back to me in small pieces, and I'm not sure I want all of them back.

I'm not saying this is better than building a company. But whatever I do next, I think I'll do it differently. Less talking, more reps. More patience with the slow parts. More respect for the gap between knowing a thing and being able to do it when someone's sitting on your chest.

Around New Year's, when I'd only just managed my first full week of six days, I came across the idea of a misogi. Once a year, you pick one thing that feels genuinely impossible for you, and you go and do it. Not a resolution. A single, scary, specific thing. So I asked myself what mine would be. I could barely get through a week of training without my body falling apart. The impossible thing, I decided, was to compete this year.

I've signed up. ADCC India Nationals, in Delhi, next month.

Just typing that makes my stomach do a small flip. I'll be walking onto a mat in front of people, against someone who's probably been doing this for years, with four months of training behind me. I have no idea how it'll go. But I've spent my whole life being the person who picks the uncomfortable road, and I'm starting to understand my relationship with fear a bit better. It doesn't go away. You just learn to walk next to it.

People keep asking me if six hours a day is sustainable. Probably not forever. But the pursuit of being really, truly excellent at one hard thing, even for a year, even if I'm never the best in the room, feels like the most honest thing I've done in a long time.

Delhi, here I come. My body has opinions about that.