Always the ace up the sleeve no matter the circumstance.
Someone looking a little down? Knock knock joke. Friend in the hospital and needs company? Knock knock joke. Someone sad at a funeral? Knock knock joke.

It's a seasoning of life, Osomatsu-kuuun. It's something that spices things up without overdoing it. Next time you're in a situation and you don't know what to do, tell a knock knock joke.