Since I’m old and a lot of you aren’t I’ll explain the reference.

Mindy’s defining traits seem to be her curiosity and her obliviousness. Mindy likes to chase things that interest or intrigue her, and though she usually has a single-minded focus on her target, she will sometimes stop her chase to question passersby about what they are doing– one repeated joke is that she will ask people “Why?” until they give up on the conversation; usually this takes about three "why"s, and she will end the conversation with her customary “Okay, I love ya, buh-bye!”

Example.

But why?

Why not?