In addition to having to stand on your chair for 30 minutes, you were open game for those sneaky little devils sharing your table to go unnoticed by the teacher and the victim to tie your shoelaces together while you stood on the chair.
When the teacher told you to sit back down, you came crashing down like a felled tree onto the wooden floor. Sometimes this would result in the feather duster being applied to your hands or the back of your legs.
What miffed me the most was that the perpetrators never got caught and the teacher never seemed to notice your shoelaces had been tied together.