Stocks as a Hobby
Unfortunately he ends up going in a bit of a different direction, but I think the idea that picking stocks is a hobby is an intriguing notion from Felix Salmon:
I had a fascinating lunch, a couple of weeks ago, which lodged in my mind the idea that stock picking, at least when practiced by individuals, is best analyzed as an upper-middle-class hobby rather than as purely profit-focused investing activity. Once you start looking at it that way, suddenly a lot of behavior, which looks irrational under most lights, starts making a lot of sense.