I found a most excellent site that allowed me to enter and track my games backlog.
I need to tweak these a bit, because there are some games in it that aren’t mine, or that I’m never going to play, but the end numbers is this: I actually complete about 20% (one in five) of the games I buy. That’s pretty sad.
The PS1 numbers, in particular, are awful. I knew that I’d bought an awful lot of PS1 games “to play later”, but I didn’t realize how few I’d actually completed.