Can you become tolerably good at something you're really bad at?

I think as we get older, we tend to shy away from things we were never good at, and move toward skills that come easily to us. Once you’re basically a grown up, can you go back and try to acquire skills that don’t come naturally to you?

I am considering signing up for a swimming class. I remember taking one as a kid and being the absolute worst in the class. I have avoided it ever since. Also school has been very good at making me feel 99% incompetent so I’m not super excited at the prospect of introducing another thing I can be bad at in my life.

Thoughts? Anecdotes? Have you acquired any skills as an adult that you weren’t sure you could? Or did you try it and decide it wasn’t worth it?