I'm not sure how to explain this. I may be the only person on the planet to get these...

But every now and again, when I feel a little drowsy and dose off just for a few seconds/minutes (usually on the train or something), I'll shudder really heavily as I wake up again. This never occurs as I come out of "real" sleep, only the little subconscious microsleeps. It's weird and I can't help but feel like an idiot afterwards because it always seems to occur in public.

Anyone else crazy?