Do you ever get that feeling about a memory, like maybe it didn't happen, like maybe you woke up one morning and sent it off to long term storage from a dream? It's disconcerting, almost in the opposite way as déjà vu is disconcerting -- the idea that rather than seeing some real event before it happened, you constructed one entirely in imagination and convinced yourself it took place. Whether due to time or emotion or alcohol, some memories wear almost a mask of nonreality, a reminder that whenever they are referenced I must question their validity. At times it's so confusing that I have to ask if a friend remembers a particular conversation or event, to double check my reality against another person's version.
And then, so very rarely, there is something so unbelievable that it forces you to question it immediately afterwards, or even while it is taking place. Waking up after ten hours of sleep after forty hours of wakefulness, and trying to remember what happened during them: Did we look at the stars, five stories up on the roof for half of a night, and touch and keep each other warm? Could it actually have been her, still curled up in my arms as the sun rose the next day? Was that real, or did I dream it?