You're not a fool. For one things, lots of folks lurk for years between posts. Or they post on threads you might not read. I'd probably be lucky to recognize 3 posters on any given 'Hobbit Hole' thread, for instance.
Also, you can change your FR handle. People do it now and then, for whatever reason. (I used to be known as Michael Rivero, but changed it once the black helicopter overflights started getting closer and closer.)
Okay, I can't back that up. But you see my point. ;-)
Oh, my gosh! Is that really you, Michael? Are you in a spider whole with A+Bert? :)