Unlike in films, a memory usually isn't a recording you can simply rewind. Much of it is pieced together loosely, more like a dream. Memory is also delicate: a question as simple as "was there a red car?" can plant a red car in the memory that was never there to begin with.
That's why I work carefully and without leading questions on things like this. It often works — for forgotten passwords or codes, for example — but I never promise it will.