Thursdays Thirteen--why do we say that?

For my Thursday thriteen this week I thought I ask "Why do we say that?"

1. Why do we say becareful after someone trips? It seems a little late to me, I've already tripped why do I need to be careful now?
2. Why do we call a tooth brush a tooth brush not a teeth brush? I for one have more than one tooth.
3. Why do we say pair of pants when there is only one? I understand it's because there are two pair of legs there but I only have one butt.
4. Why is it so great to eat like a bird when you go out to eat? I know a few young men who want their dates to eat the darn food that they just paid for.
5. And speaking of young men, my neighew called me dude. The last time I looked I was neither male nor a dude.
6. Before they invented drawing boards, what did they go back to?
7. Are Clones people two?
8. Did Adam and Eve have navels?
9. Do you need a silencer if you are going to shoot a mime?
10. Doesn't 'expecting the unexpected" make the unexpected expected?
11. Ever wonder what the speed of lightning would be if it didn't zigzag?
12. What if we told our kids go ahead and take risks....just make sure that everything turns out Okay?
13. How come you don't ever hear about gruntled employees? And who has been dissing them anyhow?