In our opinion, one of the reasons why the problem P=NP? is so difficult is that while there are good intuitive arguments in favor of P=/=NP, there is a lack of intuitive arguments in favor of P=NP. In this paper, we provide such an argument -- based on the fact that in physics, many dependencies are scale-invariant, their expression does not change if we simply change the unit in which we measure the corresponding input quantity (e.g., replace meters by centimeters). It is reasonable to imagine similar behavior for time complexity tA(n) of algorithms A: that the form of this dependence does not change if we change change the unit in which we measure the input length (e.g., from bits to bytes). One can then easily prove that the existence o...