He must have, right? In 1985 it had been 30 years since George and Lorraine saw 1955 Marty/Calvin Klein. That's a long time and memory is tricky. But i still remember stuff from high school (20 years ago in my case) pretty clearly. Some things stick with u. And an alien named Darth Vader from planet Vulcan showing up in your bedroom threatening to melt your brain if u don't ask your future wife to the dance...yeah I'm gonna say George never forgot that. Which means he never forgot marty, the guy who helped him achieve his goal. Future George may or may not have remembered marty saying goldie wilson would end up mayor, which came true. He may have forgotten what marty looked like and didn't realize he looks exactly like his son. But i gotta think all the weird stuff surrounding those few weeks in 1955 that resulted in george hooking up with his wife to be, would stick in georges mind forever. I think he must have figured it out at some point. What do u think? Watch the last couple mins of this video. Pretty good stuff. Apparently the 1st draft of the script had future george looking at a newspaper article about a near riot at the dance, which showed a pic of marty playing guitar on stage, and george put it all together. So the writers and director may have at least had it in mind that george would figure it out.