Why?

Ah, the joys of having a 2-year-old. I have recently discovered that the absense of tantrums results in an increase of questions. Normally I would be thrilled with the fact that my son is so inquizitive about all the goings on in his world, but the "Why" thing is getting on my last nerve! Here's an example of a typical conversation between me and Carl IV lately:
Me - "Alright, buddy, let's get our shoes on."
Carl - "Why?"
Me - "Because, you can't go outside without shoes on."
Carl - "Why?"
Me - "Because it's freezing cold, and if you don't put shoes on, your toes will get cold and fall off."
Carl - "Why?"
Me (rapidly losing patience) - "It's called frostbite. If your fingers or toes get too cold they fall off, and if you don't have toes you can't run or walk or kick a ball or anything. So, put your shoes on, please."
Carl - "Why?"
Me - "AAAAaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaagh! JUST PUT YOUR SHOES ON!!!!"
Carl - "Mom...not get so mad..."
Me - "Fine. We're not going outside."

Sigh. It's exhausting.
On a brighter note, Carl IV is going to his first day of nursery school tomorrow! He is absolutely thrilled! I, on the other hand, am having mixed feelings. I am so happy that he is so excited, and I know it will be good for him to have interaction with other kids his age. I am, however, nervous about the possibility of him being, "That kid." You know..."THAT kid."
"Mom, that kid hit me!" or "Who threw that toy across the room? Oh, it was that kid." He's just SO physical in everything he does, I am so afraid that he's going to get so overwhelmed at all the new friends and new surroundings that he's totally going to go nuts! Also, I'm a little freaked out at the thought that my baby is old enough to be going to nursery school!!! Alright, stop making fun of me. I know it's only 2 mornings a week, but still...the next step is REAL school. That's INSANE!!! I'll definitely update on how things go by the end of the week.