I too cannot remember NOT swimming. Every summer for years we took lessons. Joined the swim team, water ballet, certified lifeguard etc etc. I will admit to being rusty though. I haven't swum consistently in quite a few years but I bet with practice I would get right back in the "swim" as it were!
I will say I've never wanted to scuba dive. But I think that's more of a claustaphobic thing. I think I like swimming because it keeps me ABOVE water in the AIR! I think I would likely panic if I scuba dove.
Claudia