J. Leigh Bralick
Besides being able to work in my pajamas? No, seriously, I think one of my favorite things about being a writer is having an excuse to continue learning about anything and everything. Everything is fodder for storytelling, and in fact, I think the more experiences you have, the richer your storytelling can be.
I'm one of those crazy writers who likes to go and try all kinds of random things that might eventually be useful for my writing. For me, I think I do a better job with my craft when I have real experience I can draw from. For example, would I have been able to write about walking on a glacier if I hadn't ever done it? Maybe...but I can guarantee you it wouldn't have been anything like actually walking on a glacier. I just would have had no idea.
So, I've always had a slightly insane desire to try as many things as possible. Being a writer gives me a legitimate excuse. I don't know if I would say that this is hands-down the BEST thing about being a writer (which probably demands some kind of philosophical contemplation about the power of storytelling or some such), but it's definitely up there.