a paradox is what some in American-lingo will call and oxymoron, namely, an expression that has an statement with a counterintuitive logic.
the harder I work, the more I fall behind.
what the hell? if I work harder, it should be moving ahead, but, that's not the case, I'm falling behind.
so that's a paradox, how can you work harder and fall behind? is counterintuitive, contratry to logic, therefore paradoxical.