I always thought nodding off after boinking was due to the release of endorphins , the body's natural, opiate-like pain killer.
They usually get released for "good behavior" type activities, exercise, sex, etc.
Had a talk with a microbiologist sister-in-law a long time ago about how she got sleepy after breast feeding. She concurred.
Exactly. And different people get different doses and feel lethargic or focused or can go win the world.
That endorphin thing makes sense to me, not that I know what an endorphin is.