The ultimate insult is one that is finely tailored to the specific situation you’re in and only a small group of people who are probably smarter than you can understand.
We’ve come a long way as a people from “I know you are but what am I” to the niche taunts that really leave a welt on a person’s ego. There’s something about a rare jab that is just plain funnier than your average put-down and the best place in the world to find these clever insults is obviously the internet.