My dad just had a birthday and his passion is flying. He has private airplanes, which he flies around constantly, two of which he built himself. He spends time at his hangar pretty much every day. I guess you could call it his "man cave." He has a whole social network of flying buddies who have become some of his best friends. I don't think I've ever seen someone so passionate about a hobby!
Josh came up with the brilliant idea of having t-shirts made for everyone to wear to his birthday party that say "iFly Air Calvino" (His nickname is Calvino). So we all showed up in them to his airplane themed birthday party. We ate yummy food and raced little glider planes. It was a great night!