Headband of Intellect question! (My Int is too low to figure this out!)

[Iku Rex]

If you don't skill points when your intelligence drops, why would you lose any spells memorized? According to your logic, you wouldn't lose anything you already learned (or memorized).

I'm not sure what the rules are on this actually...

But keep in mind that spells are not really "memorized", they are "pre-cast" (or whatever you want to call it). What we call "casting" the spell is more accurately called "completing it" (see page 154 in the PH).

You may (?) loose spells if your Int drops because a high Int lets you "fit" more pre-cast spells into your head ("bonus spells"). Some spells could be "pushed out" if the total capacity suddenly drops.