Forgetfulness

Regular; Resisted by Will or skill 
Causes the subject to forget one fact, skill, or spell temporarily. The skill or spell cannot be used while Forgetfulness is in effect. If (for instance) a forgotten spell is a prerequisite for other spells, the other spells can still be used, at -2 to skill.

Duration: 1 hour. 
Cost: 3 to cast. 3 to maintain. 
Time to cast: 10 seconds. 
Prerequisites: Magery 1 and Foolishness.

Item 
Any item. Always on; the item causes the wearer to forget one thing specified when the item is created. The wearer will remember again an hour after the item is removed.  
Energy cost to create: 500.