One of the fun things about rebuilding your life from scratch in your 30s is realizing how much easier self-improvement would have been if you’d started in your 20s.

An example: I’m officially at the halfway point of my eight week Orange Theory Fitness (OTF) “transformation challenge” and I gotta say, I’m feeling pretty pleased with how it’s going.

This past Wednesday’s workout included a 12 minute “run for distance” – i.e. a test to see how far you can run, without dying, in 12 minutes.

Now. Please remember that, as of December of last year (that is, less than three months ago), I had never in my life set foot on a treadmill. Moreover, I literally didn’t understand the mechanics of running for more than a few seconds at a time. I spent much of the treadmill time in that first OTF class trying not falling flat on my face.

Fast forward to this week and imagine my sense of achievement when I crossed the one mile mark of my run and the timer showed just a hair under eight minutes. An eight minute mile isn’t going to win me any road races – my cursory Googling suggests that eight minutes is an OK average per-mile time for a reasonably fit casual runner – but for me it represents gigantic progress. From zero to an eight minute mile in less than three months.

And yet, as I raced past that first mile, then looked up and down the treadmill line to see how my fellow runners were doing, I couldn’t help think what OTF must be like for, say, a 25 year old. Specifically, I couldn’t help comparing the energetic twenty-somethings pounding out their twelve minute runs with myself at their age.

Christ, when I was 25 I could barely cross the street without taking a rest. How much fitter and stronger might I have been today if, instead of drinking my 20s away, I’d have spent that time and energy in the gym?

A similar thought occurred to me last year when I went to visit my brother and his wife in Montreal.  Like most British people, I studied French for years at school. I scraped an A grade at GSCE level (age 16) and, in my mind at least, still retained enough vocabulary and grammar to comfortably navigate a French-speaking city. Bonjour! I would say, to the Francophones. Bonjour!, they would reply, veux-tu de la poutine?

And I would understand what they were asking!

Nope.

Not in the slightest.

It turns out that language is a muscle like any other. If you don’t use it for 22 years, it atrophies down to nothing.

So on my return to San Francisco, I signed up for weekly French lessons. I’ve been taking the classes for about 12 months and am now finally at the point where I can talk in French, reasonably competently, for an hour about any topic that’s on my mind. As with the running, this represents huge progress. I’m both pleased with myself, and grateful for my tutor, Elisabeth. (Not for Elisabeth mundane topics like ordering bread, or asking for directions to the nearest swimming pool. In recent weeks we’ve discussed, en français, topics as varied as Brexit, the Yellow Vest protests, Netflix, and San Francisco income inequality.)

And yet. And yet.

As with OTF, I can’t shake the nagging frustration at how much more fluent I might be at this had I stuck with learning French after leaving school.  Or spent a few pounds on French lessons in my 20s rather than wasting those same pounds (and 20s) drinking,

The answer is much more fluent. Just as, duh, I’d be much fitter had I been running since my teens, or much smarter if I’d read as much in my 20s as I do today.

It’s hard not to see my 20s as a decade of wasted opportunity. The what-ifs never stop coming, and are only made worse when – as happened at OTF this week – I feel like I’m actually making progress with something.

And of course it’s a ridiculous, and unhelpful, way to look at sobriety. For one thing, it’s a waste of time. Wasting time worrying about wasted time must surely be the definition of compounding a problem.

For another thing, I still managed to pack a ton into my “wasted” 20s, including writing a weekly column for the Guardian, authoring a dozen books (one of which almost became a movie), and moving to the US. That’s pretty impressive for a guy who could barely bend down to tie his shoelaces without tumbling into a gutter.

Mostly though, it’s not a helpful thought process because it’s not true. The reason I’m so engaged in OTF or French classes today is precisely because I wasted all that time. I wrote about this back at TechCrunch : How the problem Silicon Valley’s obsession with living forever is that death is such a great motivator.

It’s only because I wasted so much time that I’m so driven to pack as much as possible into my 30s and 40s. The idea that a sober version of me would have spent that time learning French or running on a treadmill rather than, say, watching reality TV or eating McDonalds is just silly. There are plenty of out of shape sober people, and countless non-drinkers who lack the motivation to write a tweet, let alone a book. No reason to think I wouldn’t be one of them.

So instead of feeling frustrated at the time I wasted, I’m going to focus on feeling glad for the time I didn’t waste. Glad that ten years ago, at age 29, I decided to get sober, rather than waiting til I was 39 or 49.

If you’re 49 and just got sober, then you can be glad you didn’t wait til 59 or 69. Hell, I don’t care if you’re 99 years old when you quit: Every minute of sobriety you’re able to salvage and exploit is a fucking gift, and one that non-addicts can never truly understand.