The first thing people ask me is, "why?"
It's not a particularly unusual thing to do. Something like 1% of the population has run a marathon. There will be around thirty-six thousand runners there on Sunday.
But still, even experienced runners tell me I won’t enjoy it, and it’s a lot of effort that achieves nothing obvious, so perhaps some justification is expected.
The first reason is to move the goalposts.
There's power in being able to face any experience, whether it be disaster, heartbreak, or just a bad day at the office, and say "Well, I've had worse". This sounds glib, like something from a Little Book Of Wisdom or a Hallmark card, but once they're backed by real events, those words have power. The Spartan Beast was a deeply emotional experience for me. Lying face down in the mud next to a wall I'd just fallen off, cold, alone, in darkness, I was able to think "This is going to end, because I am going to end it".
Your identity is what you have proved to yourself.
The other is more subtle, a side-effect I hadn't been expecting. Training for this has changed my relationship with my body. Faced with a challenge of this size, I've been forced to work as a team, to listen to my body, and to respect it. Also, having triggered every kind of alarm there is, from low fuel to muscle damage to temperature stress, I know what they all sound like, what to do about them, and when they can't be ignored. It's not until you really push your hardware that you know what it can do, and what it needs.
And finally, there's proof of work. Words are cheap. But mental illness has kicked around a few people I dearly love, and this is a way of saying "Y'know what? I care this much" - about them, and about the work Mind is doing.
So that's why. I hope I remember that when I'm out there.