I first started playing poker when I was 18, although it was only with friends at that point for a laugh and mainly for beers as opposed to actual money (winner of the game took the winnings but it was customary for them to buy the first round or two at the pub next time we were out).
Playing properly I first played when I was 24, but had a bad experience and stopped playing properly for quite a while and then only dabbled here and there.
Playing properly and regularly, I started at the end of last year and I'm currently 34.