Well, I definitely could swim; I learned at school, when I was about 11. Now? I couldn't say for sure, since I haven't done it in a couple of decades, but I'd assume it's one of those skills that doesn't really leave you.
I didn't know how to swim until I was like 12. I was afraid of a lot of things when I was younger, deep waters was one of them, but once I just jumped in, I became a fish