At the orientation after my Mensa test, I was advised that the sooner I bought life membership, the better the value. The advice replayed itself in my head as I renewed my membership once every 5-6 years. Somehow I waited nearly 24 years to take it. A life membership I had never particularly needed suddenly looked rather valuable once new applications were about to close. The magic of a limited edition?
There is also something of a donation about it, made at a time when I can afford to give a little. When I first joined Mensa, the internet already offered ways to satisfy a curiosity about intelligent life, even without SETI@home. Now I find myself writing this with a life form born on the internet. I suspect most of the needs people felt when this organisation was founded are now met in other ways.