Weird toddler behavior unexplained

I love my son, and generally I am able to understand him (except when he doesn't want me to understand him). Just when I think I have a handle on his behavior, and what I need to do with him, he starts being all strange.

This morning, he hopped around the house yelling "Ribbit" and "I'm a kangaroo, kangaroo." I am unclear what prompted such a joyful hopping. And I don't know how to stop it either, because when it came time to put his shoes on to go to day care, he wouldn't stop hopping. when I firmly grabbed him and planted him on the sofa, he started bouncing as best he could. I am so confused!

And this combines with last night, when he was bear crawling around the house (hands and feet, bent in half) and yelling "roar, big boy lion" and "dinosaur." He didn't tell me why, he just kept doing it. Up and down the stairs he went, around the house....it was so odd.

He also does the following things:

1. Eats food and says "yum I love it" but then doesn't want to eat it after saying "yum."

2. Runs naked around the house whenever he gets a chance (shocker).

3. Uses the potty occasionally at day care, and refuses to do it at home because he says he likes diapers.

4. Giggles like a maniac for no reason.

5. Clings to my leg and tries to pull my pants down.

6. Plays catch with his stuffed animals.

7. Sits and cuddles with his bouncy balls.

8. Insists that pianos should be played with his toes - and then gets mad when I don't allow this.

9. Tries to color with the crayon between his toes.

10. Opens and closes doors randomly.

Some of his odd behaviors I understand - his shirts go on inside out because he wants to dress himself. His pants go on backwards for the same reason. He likes to play with play dough...who doesn't?! He loves to see his artwork on the wall, so we have a ton of it posted all over our house. If you come over - you are going home with a Nicholas original.

He is a very smart, verbal, intelligent boy. But sometimes I just don't understand him. He needs to have a balloon over his head so I can understand what he means and what he wants. He cries and says he's not hungry, but if you put food out he eats it all up. Or he says he's hungry, but he won't eat.

Two-year olds are a mystery that have never been solved, and regardless of what the experts say, I think they will remain a mystery that is never solved.