It’s very simple. Once your uh, dam bursts, your iq jumps by about 50 points and you’re firing on all cylinders intellectually for a while. But after some time passes of not doing so, you get horny, and your intelligence steadily decreases. Post nut clarity refers to that sweet spot right after busting when you can use your whole brain and you’re at your smartest
Testosterone tends to have some bimbo-ifying effects when it builds up e.g. saving up a load. The rush of androgens that happen on orgasm kind of cut through those. Not to mention all the blood that gets returned to the rest of the body since erectile tissue has to shunt off its own blood pressure to sort of inflate the dick, like a very nebulous water balloon