Aaargh! A dose of lurgi has stalled the writing so here I am wasting time instead...
Where do you get your characters? Are they really you in disguise?
It's an interesting thought. Some MCs I've read have very obviously been richer sexier versions of their author. For some people it's a good wish-fulfilment exercise. One recently separated middle-aged man of my acquaintance wrote an entire novel about a fabulously wealthy recently separated middle-aged man who did nothing other than have affairs with gorgeous adoring young women and bitch about his dreadful ex-wife. Some authors claim to be the antithesis of their MC - I'm thinking of Iain Rankin whose Rebus is based on men he grew up knowing rather than himself.
But aren't all our characters really parts of our own personalities? We need to get into their heads, so to some extent they must be part of us or we wouldn't understand them. We may not make the same choices they make, but that's where imagination comes into it.
The MC if The Bookseller is a man, so he obviously isn't me. I think I am in the book though, just not the main character. But I recognize his paranoia and neurosis - they are universal and why (I hope) people will read the book.