Our two youngest boys are in camp and the oldest is hanging out with some friends, so we had just our daughter. We drove to another city to do some visits, a three hour drive.
My daughter is usually fairly quiet, but all on her own, she talked non-stop.
Finally, my husband asked her, "Girlie, are zebras white with black stripes or black with white stripes?"
She thought for a few minutes, and then came back with a question of her own: "Are you talking about boy or girl zebras?"
He answered that it didn't matter.
So she wondered about it a few more minutes and then said, "Because maybe girl zebras are white with black stripes and boy zebras are black with white stripes."
That explains it.