He has to poop, and doesn't want to miss it.
He has gas, and needs to be awake for that too.
His stomach is slightly uncomfortable because of one of the above.
He heard a scary noise.
He imagined a scary noise.
The ceiling fan is distracting him.
The ABSOLUTELY NOTHING on the ceiling is distracting him.
He woke up with his arms swaddled and is pissed.
He whapped himself in the face with an unswaddled arm, and now wants to be swaddled again.
He has a pacifier in his mouth and can't figure out how to spit it out.
He spit his pacifier out and wants it back.
His mom is so fascinating, he doesn't want to miss a second of her life.