Shitty Ask Science

Let's try a proof by contradiction: begin by assuming that potatoes have the ability to think, then derive a contradiction using logical inferences.

If a potato had the ability to think it would find my personality respulsive, as any thinking creature does.

If a potato found me repulsive, they would do everything in their power to locomote away from me, or at the least not attempt to take root.

Based on the potatoes that I purchased at the supermarket last week and forgot about, I can say that potatoes will attempt to take root in my presence, a fact incompatible with sentience. We've arrived at a contradiction, therefore potatoes lack sentience.