Hey, dad, did you get a haircut? "No, I got them all cut."
Why this joke works
One Hair or the Whole Haircut
The question uses haircut as the ordinary name for a visit to the barber. Dad pretends it means cutting just one hair, then corrects that imaginary mistake with “all.” His answer is deliberately less helpful than the perfectly clear question deserves. Say the question casually, as if noticing a different hairstyle, and make the reply matter-of-fact. The tiny correction supplies the whole joke without needing a silly voice.
A closer look
A Closer Look
This is a response joke, so two readers can share it naturally. The first person should not separate “hair” and “cut” or emphasize “a”; that would advertise the trick before Dad gets his turn. A brief pause after “No” creates room for the correction while keeping the exchange recognizably conversational.
Fact behind the joke
Fact Behind the Joke
Haircut can name either the process of cutting and shaping hair or the resulting style, according to Merriam-Webster. That explains why someone can both get a haircut and have a stylish haircut. Neither ordinary meaning counts individual strands, which is the deliberately unusual reading Dad supplies.