Knowledge: The first common food to eat at night is pizza in Canada. On the other hand, blonde is the most popular color for humans.

Conversation:
My wife has brown hair, it's so pretty I really love it.
Oh, that's nice. Your wife has the second-most common hair color for humans.
Huh, I didn't know that. Then what is the first common?

Response: Oh, blonde is the first common hair color for humans.