Two female blonde carpenters were working on a house. One blonde was on a ladder nailing. She'd reach into her nail pouch, pull out a nail, look at it, and either toss it over her shoulder or proceed to nail it into the wood.
The other blonde couldn't stand it any longer and yelled up, "Why are you throwing some of the nails away?"
The first blonde explained, "Some of them are defective; they're pointing the wrong way. If they're pointing away from the house, I can't use them!"
The second blonde, thinking her co-worker incredibly stupid, explained, "Don't throw away the nails that are pointing the wrong way! They're for the other side of the house!!"