Pseudoscientific theories do not actually have any explanatory teeth

"Rather counterintuitively, Popper also thought that scientific theories cannot ever be proven, because they are always open to the possibility that a new observation—hitherto unknown—will falsify them. For instance, I could observe thousands of four-legged dogs and grow increasingly confident that my theory is right. But then I could turn a corner and see an adult two-legged dog: there goes the theory, falsified by one negative result, regardless of how many positive confirmations I had on my notepad up to that point. In this view of the difference between science and pseudoscience, then, science makes progress not by proving its theories right— because that’s impossible—but by eliminating an increasing number of wrong theories. Pseudoscience, however, does not make progress because its “theories” are so flexible that they can accommodate any observation whatsoever, which means that pseudoscientific theories do not actually have any explanatory teeth."