"Ooh, crazy's what they think about me

Ain't gonna stop 'cause they tell me so

'Cause 99 miles per hour baby,

Is how fast that I like to go."

This customer asks you for something, and while you're getting it for them (which usually takes less than 2 minutes), they just disappear. You look and they're wandering around with their shopping cart all the way on the other side of the store. Then you're left waiting around until they remember to come back.