Is the Proton Made Out of Up and Down Corks?

Most of the energy inside the proton, which is what contributes to its mass, is due to gluons. The electron has a heavy cousin called the muon and it has an even heavier cousin called the tau. And that's true of all of these fermions. We have no idea sort of why it is that way. What we can say is that if the universe wasn't this way, it would look very different.