By means of this spell, a wizard bestows a special curse on a spellcaster that destroys the subject's ability to comprehend certain spells. Lost spells cannot be rememorized or even cast from a scroll; the mind of the victim simply cannot understand and enact them.
Spells known to the victim are lost at random, beginning with spells currently memorized. One spell is lost instantly. An additional spell is lost every 10 days thereafter until the victim forever loses all spellcasting ability. Priest spells are not subject to this spell.
A remove curse spell does not affect this special curse; a limited wish or wish spell is necessary. Imbibing an undiluted sweet water potion, (not its usual application, hence this remedy is known to a few) will halt but not reverse the effects of a curse of forgetfulness.
The reverse of this spell, bestow remembrance, reverses the effects of a curse of forgetfulness, a forget spell, and similar magics.
Notes: Uncommon for witches; otherwise very rare.