I was 6 years old. 55gal with an Oscar and and Angel fish. The Oscar lasted 4 years untill my uncle decided to feed him a half of a hot dog. He bit off more than he could chew....No pun intended.
Was 16 and decided that a oscar could live in a 10 gallon. Oh how that fish died. Stupid Meijer selling those fish to people once like me that were inexperienced. Got a rat, then a dog, moved into a new house and bought a new tank. The rest is history.
I had to be 5 years old when I started. I got a AGA 5 gallon kit with a betta. I was constanly around fish since the day I came home from being born. My dad and mom both got me into the hobby so it's a good thing. The reason they gave me the 5 gallon is they wanted to see if i would do water changes and do the daily needs for a fish to survive and I did so they helped me along in the hobby ever since.