For me: learning Arabic. I had a teacher who was SO not a micro-manager; he told us to just work on what we knew we needed to work on, and that was exactly what I did. And it turns out that I'm pretty good at it-- or, at least, I thought that I was for long enough to get me off the ground. Think of it this way: if there is something that many, many people view as insanely difficult, but you just find it to be hard but enjoyable work, wouldn't that make it really, really fun?
For Mom: the summers she was a fire lookout in California. She had a dog named "Cat" for a companion and a '22 for taking care of rattlers and other intruders, and she was in radio contact with headquarters; but she was physically alone for most of the time, in charge of watching for smoke which would indicate a forest fire in the making. I'll try to blog some of her fire lookout stories soon.
For Dad: the summers he was a boy scout camp counselor up at Camp Bear Lake, on the Utah-Idaho border. One of his younger brothers (six years younger) was also working there, and the kids would ask all the time if they were twins-- the grownups knew that they weren't, but they would mix them up anyway. The camp had a great spirit of camaraderie, respect, and competence, not to mention that they got to be outdoors a lot.
Is it any wonder that my parents' preferred summer vacation activity for our family was camping? Or that I became a language teacher?
That title was also a genuine question: I would really like to know. What IS the funnest thing you've ever done? (Or, since this question is really just a conversation starter and I'm not going to hold you to your answers at any rate: what would the top three contenders be?)