Fish keeping about 20yrs on and off. As for my age, I'm half a century and this year I will be 49 and counting down to my youth again. After all we are all young at heart.
I'm 31. Started keeping fish when I was 11, kept them until I was about 17, then starte again just very very recently, as in December of 2004. So, umm, Fishkeeping for 6 years and change.
I'm 30... The earliest tank I can remember caring for was a 20 gal long full of guppies and itty bitty snails when I was about 10. One of the weekly chores that my brother, sister and I would have as kids was that we each had to crush 10 snails in the tank so the fish could eat their bodies... It was my Mom's method of snail control! And every week, my sister would barter with my brother and me for who would crush her snails in exchange for a different chore.. She could not bring herself to stick her hand in the tank, much less crush a snail... Oh the concerns of childhood!
I still have that 20g long in my basement, empty, right now! Since then, I cannot remember a time that I've never had a tank running. Whether it was a tiny 2 or 3 gallon on my desk at my first "real" job, or my 5.5 gallon, a 10 gallon or a 29 gallon.... Almost always with small fish, guppies, tetras, neons, dwarf frogs, bettas...
My 125g that I got for Christmas is my biggest tank ever. It's also the very first time that i've kept most of the kinds of fish that are in there!