[CharacterCounts]

I didn't know this was such a mystery. They should have asked me -- I worked this out years ago.

I invented the "clapper" but forgot to patent it.

[Erasmus]

I invented the "clapper" but forgot to patent it.

Prior art: Notre Dame.

[Zeppo]

I invented the "clapper" but forgot to patent it.

I'd bet that a bunch of WWII GIs caught it before you invented it...