I started at about age 12 (hard to remember now that I am OLD!). I have had
some periods with none, but I guess I agree that its for old-folks, I just started again and I am 62 -- I guess that counts as OLD
Anyway, yes it can be expensive if you want it to be, it can be inexpensive too -- depends on how you deal with things. I do lots of DIY (lights, co2) -- but any "hobby" that does not take time and effort is not really a hobby. I DO love walking around my LFS, and sometimes I even buy something, but just looking is fun too -- I don't think I have ever felt negatively about the hobby, even the time my saltwater tank drained all over the floor due to a stuck fluval -- while I as on vacation and a neighbour was looking after it -- maybe the neighbour had a negative thought though. Anyway, I think its a great hobby and you can have fun playing with it or just looking at it or both.
some periods with none, but I guess I agree that its for old-folks, I just started again and I am 62 -- I guess that counts as OLD