The Universe is made of 12 particles of matter, four forces of nature?

Suppose that little things

Behaved very differently

Than anything big

I'm afraid it isn't quite so simple as that. Yes, you are right about the 4 fundamental forces. However, you are way out in your estimate of sub atomic particles. There are 6 "flavors" of quarks, 6 leptons, and 13 gauge bosons. Also, we mustn't forget that each particle has it's own anti-particle. The whole forms what many physicists have dubbed "the Particle Zoo". Many attempts have been made to reduce the number, but in order for things to work the way we see them work, those particles have to exist. In fact, there may well be other particles besides these. Are you familiar with the old rhyme? Big fleas have little fleas upon their backs to bite 'em, Little fleas have lesser fleas, and so ad infinitum!. Every time we think we have found a basic particle, it turns out to made up of smaller particles. Like all physicists, I can't wait to see the results from the next generation of hadron colliders!

Erica -- 13 gauge bosons? I count only 5 elementary ones, plus the Higgs boson and the Graviton. Are you including the supersymmetric ones? Those are still rather hypothetical.

Quantum theory... so stange and bizzare that even Einstein couldn't get his head around it.

is it really?