Quote Originally Posted by Khanderas View Post
Feeblemind. Does not go away/supressed in an antimagic field.
Means your brains are scrambled but the enchantment is gone.

The spell takes a metaphorical potatomusher and destroys the parts of the brain that has the smarts. Remove the potatomusher and the damage is still there.

DM is always boss though.
Break Enchantment can specifically undo Instant Spells.