Well tbh, I'd say it's more important he has a good memory; even if he's shit at writing, as long as he can either tell his stories for a biographer to write down, or write them down half-arsedly for a good editor to polish. In this case, I don't care about whether he's a good writer, but whether his stories are good; the rest can be fixed by others.
That was my first reaction too. I would love to read about his adventures. 23 years is a very long time travelling. I am not sure of my facts but Alexander the great traveled (or was on an expedition) for about 15 years. He has far surpassed that feat.
I was thinking the same exact thing. Also, I hope he kept detailed journals, at least, of all the time he spent dodging danger.
I enjoyed reading some of his status updates on Facebook, especially about his date with a Muslim Chinese woman. https://www.facebook.com/mike.s.bown