I'll tell you when you're older
A way to tell a kid they're not smart enough to know the answer right now
My dad said that when I asked why he had a crush on my mom and he was already mad at me.
My uncle said that when I asked why he kept eating pizza for breakfast and he didn’t want to explain it.
My cousin said that when I asked why her fish was floating on the surface and she didn’t want to admit it.