Waking up in a bundle of blankets as a child in a hospital is quite jarring. It's even more jarring when you were just in an interrogation room, getting--surprise surprise--interrogated for some codes to some uber secret government lab off the coast of the US.
But ever the adaptive operative, Peter wasn't about to get down...until he heard people talking about how his new body's parents had just died. His mom after giving birth to him and his father after a heart attack presumed to have been brought on by losing his wife in front of him.
It got even more complicated after they mentioned what he presumed to be his new name: Peter B. Parker.
...Otherwise known in the marvel universe as Spider-Man.
He tried to deny it for 4 whole days, saying that was absurd - You can't be reborn as a baby AND be in the Marvel Universe, right? Right?! - but he was proven wrong when he saw an advert on a nearby TV about...Stark Industries.