Let's be honest, children ask too many questions. It's a beautiful thing how creative they are, but it can also get freaking annoying to explain every single thing in the world to them. If you get them down the "why" train you'll never be able to escape.
"Mommy, why can't I go outside?"
"Because it's freezing"
"Why?"
"Because temperature is under 30 degrees"
"Why?"
"Because it's winter"
"Why?"
"Because we're in the northern hemisphere of Earth"
"Why"
"AHHHHHHHHHHH"
Sometimes it's just easier to throw in a white lie.