It takes 10 years to master programming, but 24 is not too late at all. I know a lot of people that started in their twenties and now are good programmers.

My problem instead starts to be how much time I can continue to do programming for work. I'm 32, it seems fair to me to continue for another 10 years, but should I switch at some point? My dream is to turn myself into a teacher around 45 opening a programming school, but probably children can learn faster just by internet than with an old teacher ;)