The omigod it was *there* all along moment

One thing that has always impressed me in movies is when they can have the solution to a puzzle given to the audience and you don’t realise until the end what it was.
I know I can explain this better but I’ll have to give some spoilers, so…

In the movie Deep Red the killer is actually seen at the beginning, the hero thinks he saw a creepy face in a painting, but it was actually a mirror.
Trauma, by the same director had a similar surprise.
In the TV show Twitch City one episode had a death metal band playing a song that was driving the psycho roomate crasy because he recognised it, at the end of the episode he finally figures out what the song was and starts to sing “Don’t sleep in the subway darlin’…”


So can anyone name some other examples of this?
Feel free to spoil away if you want, just warn of spoilers.

Hey, welcome to the boards, grendel. There is a similar thread like yours that’s active right now, but it is focusing on the best trick endings ever.

Anyway, I think the Sixth Sense is one of the best “there all the time” movies I’ve seen.

Citizen Kane did it also.