I'm with Gingerwizard. I'd explain it a little differently though:

The math can never be outright wrong. But the quality of your math can vary based on your information. We all know this, so often we question our math when a decision seems marginal since our information is always a little sketchy. In a ring game, a +EV decision is always right, even the "call $1 into a $100 pot" decision. This assumes that your BR is not down to your last buyin, which assumes that you are playing stakes that you can afford. Our goal is always to make the best decisions we can with the info we have.
As to "knowing you're beat" but the math says call: why do you know you're beat? I'd submit that it is mathematical, in the sense that it is a result of a pattern. You've played gazillions of hands of poker. You've seen skads of similar situations. Your internal alarm klaxon is blaring that you're beat. On the surface you are evaluating your opponents actions which seems non mathematical. But I think you're recognizing a pattern and patterns are mathematical.
In poker, a lot of our math is less like x+y=z with 2 known variables and more like advanced physics where some variables are known and some unknown and some are approximations that change as information gets better.
I'd also say that this is what seperates the truly gifted poker players from everyone else. All of us can, and most of us here have learned to do the basic highschool math of poker. If any of us are ever going to take the poker world by storm and become the next Negranu or Ivey we have to master the "physics" as well as the basic math. It'd be cool if someone from FTR could do it some day. My mind doesn't work that way so I'll just stick mostly with the math