Learn FOR Fun

What are the things you do for fun? I surf, skateboard and tumble (floor gymnastics) for fun. I also enjoy having cookouts, going to the beach, and doing other leisurely activities like anyone, but hobbies that require skill to display seem to be more special and give more joy than say watching TV. Have you ever considered academic learning as something fun? I don't think it beats surfing a wave or doing a flip, but the fact that it requires a skill to be developed and is useful for advancing research, technology and building things gives me some satisfaction. Is there an academic pursuit that you enjoy doing like I enjoy science and languages?