Joke Collection Website - Cold jokes - I only know what 25 letters are.

I only know what 25 letters are.

I only know 25 letters, which means I don't know Y.

This is a cold joke, because y is homophonic with English why.

The original words are "I only know 25 letters", and the other person will ask "Why?" Then answer "I don't know Y", which means "I don't know why". It's a cold joke mixed with English homophones.