I picked up a fly rod shortly after my 50th birthday 3 years ago and started tying about 6 months later. Took the LRO fly-tying classes Dec. 2010 - Feb. 2011. Still a rank beginner, but I'm having fun with it. If I keep at it I'll have something to keep me busy when I get OLD. (By definition, OLD is 20 to 30 years older than you are at a given time.)
Fly fishing - it's cheaper than a bass boat!