Strange Hobbies?

[Dossta]

MysticMoon's recent foray into tomb raiding has made me wonder.  What are the strangest hobbies that you have a) ever participated in and b) ever heard of?  Could be a good way to spice up a character or NPC, too.

Here are mine:
a) Creating 2D-isometric pixel art.  There's just something about building an image one pixel at a time that I find fascinating.
b) Fierljeppen.  It's basically a sport based around crossing a body of water with a long pole.  https://www.youtube.com/watch?v=UhTMEePk6D4

[MysticMoon]

Aw, chasing down ancient Mayan burial chambers isn't all that strange, is it?

a) Gregg shorthand. I've been intrigued by it for years and finally decided to buckle down and learn it this last January. It took me about 8 months to get the basics down and it will be much longer before I am any good at it. I wrote the first draft of Amazons and Orcs with it and I used it to write the phrase "Show me time itself" as the glyph in The Glyph of Tarnos Krae.

b) I'll have to think about this one.

[Scrasamax]

My wife collects and shows 1/9th scale model horses.

Breyerhorses.com

[MysticMoon]

a) Creating 2D-isometric pixel art.  There's just something about building an image one pixel at a time that I find fascinating.

Any examples you'd care to share?