As a rule of thumb I rarely if ever, base a character entirely on myself. Mark does share my contempt for celebrity shows and the desire for peace along with a love of nature. I also say that P A Canella is based closer to me, Mark is too heroic to be based too closely on me.
A few days ago I wrote the story "Algernon & Bertie," http://alsdomain.weebly.com/4/post/2013/04/algie-bertie.html in this story, the character Algie is based close to me. Although my room is not as cold as his lodging house, by mid-afternoon I need a light on, I had the accident I mentioned and the after-effects of the injured shoulder and I do stay in bed late for the same reasons as Algie does. I also stay in bed late because being a writer( laughs to himself), I have no schedule to keep and often work through the night which is useful as I don't sleep well and most of my friends and colleagues are in the USA.