In elementary school science we learned a few things about the tongue and flavors.

We learned that all food falls among the only four flavors: Salty, sweet, sour, and bitter.

I can prove that wrong with this unanswerable question:
Describe the flavor of a white onion using only the terms, salty, sweet, sour, and bitter.

We also learned that each of these flavors has a designated part of the tongue that can only taste that flavor and nothing else.

I can prove that wrong with this unanswerable question:
Why is it that you can taste any food on any part of your tongue?

And don't tell me I'm the only person who can do that. That is highly unlikely.