After he had figured in admission prices, how much he ate and drank at the track and transportation costs, at the end of that great, dream year he lost $50.
That's when he permanently gave up horse racing.
Now here's the thing... I would have seen that as a favourable outcome... He went to his chosen sport, had meals, drinks, admission and transportation, for a year, and it only cost him $50. I know plenty of people (I used to be one) who go to race tracks, follow the horses, trainers and jockeys in the sports newspapers and magazines and on TV, eagerly discuss great races they have seen, maybe put a little bet on just for the fun, have a burger or hot dog and a beer or two, and happily spend about the same amount of money as a football or tennis or motor racing fan. You look at it that way, you are having fun, a day out, see some pals, it's OK. If you go into it with the idea that you are going to get rich, you could easily wind up with your ass hanging out of your pants. Of course your friend had a lucky year. Maybe he reflected he could just as easily have a bad one, and decided to quit for that reason.