I started in 77-78, but my collection didn’t expand much beyond D&D, Traveller, and Champions until the early 1990s. At that point, it exploded! By the turn of the century, I owned books from 200 different RPGs.How long do you hold onto a game book you don't like before unloading it somehow?
And there it stood for a good decade or so, when I finally divested myself of about 40 systems worth of books. I donated a lot of them to the USO, along with some polyhedral dice sets.
Since then, I’ve added a couple new systems.
But the real answer is, “it depends”, because I absolutely still have my earliest acquisitions. The stuff I donated was all bought post-1990.

