I made a pencil with two erasers. It was pointless.

Behind the Groan

A Pencil Without a Point

A sharpened pencil needs one writing point, but putting an eraser at both ends removes that useful tip. “Pointless” therefore describes the pencil's physical design and says the invention has no purpose. Deliver the first sentence like a sincere report about a clever new school supply. Pause before the verdict, then say “pointless” plainly. The joke works best when the second meaning arrives without extra explanation, helped by the listener picturing both erasers.