Because they've been lied to all their lives about how long "8" inches is.
A dead centipede.
Disclaimer: I don't know how well this joke will work in english. What's yellow and lies in a pond? An excevator. You don't think this is funny? Neither does the operator.
If it's red on top, fire in the hole.
The hornier, the better!
A mousetache.
Don't we live in every room
Because it's on the house.
Because they've been lied to about what 8 inches look like their whole lives.
A: 6 inches is medium 8 inches is rare.