A couple of falsities for me:
Until seeing the reruns on GSN, I always thought Johnny's podium was white and had TPIR logo on it.
I always thought Jim Perry, Art James and Geoff Edwards were Canadian due to their shows being taped up here. It wasn't until later that I found out they hosted other shows.
For Canadians, I thought that "The New Liar's Club" and "The Next Line" were the same show, only that they updated the set for the later seasons and added a piano for Pete Barbutti.
A false memory-ish, but when Barker hosted TPIR, the shooting style made the studio look huge. The newer style shows how much smaller it really is. Post-Barker TPIR killed a lot of childhood memories for me.