Topics about which I had extensive debates with other kids as a child:

1. Whether or not it is okay to pee or poop while eating or drinking.
1.a. Does the fact that cows do it apply to our conclusion?
2. Whether or not it's okay to return a plate to the cabinet after licking it completely clean.
2.a. Do germs exist, and how do we know?
3. Whether or not girls can be doctors and boys can be nurses. (My brother is now a nurse.)
4. Whether or not a watermelon will grow in my stomach after I swallow the seed.
5. Whether or not it is possible to "blow out" a red light like a birthday candle (to turn it green. This always worked eventually!)

How 'bout you?