This happens to me almost every time I watch a movie. Best example was the movie SAW.
I'm watching the movie and I realized that I knew Danny Glover's partner "Sing" from somewhere. I'm still watching and enjoying it, but my eyes were going up and to the left while I worked on where I had seen him. I could picture him saying a movie line, but the words weren't spoken.
After about 20 minutes, the quote "No problem....just rush hour" went thru my head. I finally realized this guy played "Sang" in Rush Hour and he had blond hair.
Another one was the last X-Men movie. The kid who played the young Warren Worthington (Angel) looked really familiar, and eventually the quote of "I can't wait to start a dodgeball game!" hits me. Yep, he played the kid in the Patches O'Hoolihan video for the Dodgeball movie.
Does anyone else have something like this? It's like having a mental itch that I can't scratch.