Why do people keep running over a string a dozen times with their vacuum cleaner, then reach down, pick it up, examine it, then put it down to give the vacuum one more chance?
because we except our vacuum's to do what they are made for. To pick stuff up off the floor. I'm not saying I except it to pick up a ball of yarn, but a stray thread from a sweater or something should go in!
I fight this urge. I normally will pick it up and somehow hold it until I make a trip to dump the contents of the sweeper. But I have this urge to throw it down for the sweeper to pick up. Why I don't know.