Yesterday I drank half a pot of coffee and took a nap a short while later. It gives me energy but doesn't really prevent me from falling asleep. Anyway, I woke up in sleep paralysis for about two or three minutes or more. I knew what was happening and it's happened plenty before so it wasn't scary, but it it got very frustrating. I told my dad about it and he immediately asked me if I had caffeine before I slept. Apparently the same thing happened to him a few times when he was younger and scared him. He drinks tea before bed but he avoids large amounts of caffeine for this exact reason. Is this a common side effect? Also what do I do when I wake up in SP? I don't necessarily want to get out of it if I can shift myself into an LD . If I relax enough will I see hypnagogic imagery?