My dad, who is 70, is really into geocaching. My mom knows when he's getting ready to go out hunting when he sits in front of his computer all day being real quiet, then come out the next morning with a handful of printouts and his GPS.
He's become good enough at the computer to post and retrieve info on the geocache site, and for a non-high school grad of his age, I think that's something.
He makes and hides caches too. He drills out logs, puts a pvc pipe in them, then fits a plug over the opening. He also makes fake boulders by spraying expanding foam over plastic coffee containers,rolling them in gravel and dirt, then aging them under shrubs in his yard until he's ready to hide them.
It keeps him physically and mentally active, and (mostly) out of trouble.
It works for a lot of people, and gives them a community of people to correspond with, same as here.
Personally, I'd rather go out day after day looking for "real" hidden treasure and come home empty handed than bag several caches in a day, but different strokes, baby,