I guess it's always uncomfortable to discover you're not as individual as you thought. But it really bothered me. From one perspective, I was an independent animal, exercising free will in order to elicit predictable reactions from an inert vending machine. But from another, the vending machine was choosing to withhold snacks in order to extract predictable, mechanical reactions from young men. I couldn't figure out any objective reason to consider one scenario more likely than the other.