Snow Bank

Talking to a 4-year old, you don't realize all of the things you say that seem common sense to you, but to a 4 year-old, the saying should be even more common sense than you think! (did that make sense?)

Anyway, driving home from work yesterday:
Me: "Uh oh, that car got stuck in a snow bank"
Hunter: "No, it just has to go backwards"
Me: "But it can't because it's up on the snow bank"
Hunter: "Mom, (very matter of fact, like duh Mom) a snow bank is snow shaped like money, the car is just stuck in the snow"

Now you know what I mean about what should be common sense?? So somebody please explain to me why it is called a snow bank and who would have named it a snow bank, because clearly a 4-year old has more common sense than whoever named it and us who say it!