I was going to tell you a joke about a pencil, but now it is pointless.
Pointless Pencil
Explanation
Explain Bear
Okay, listen up, buttercup. The joke is funny because "pointless" has two meanings. First, a pencil needs a point to work, and second, if something is pointless, it has no purpose. It's like when you try to understand advanced math. Pointless, right?