Well my dad got his in '79, as born in '84 have grown up with them, got my first one in 2005, a 87 4/4 4 seater at 21 (just).. after a few miles and lots of use, upgraded to a 1996 +4 4 seater in Nov 2013, what an improvement.
I would say I will likely always have one in the garage, at the minute finances mean its the only car in the garage..