The possibility of anything you can think of (and everything you can't think of, too) exists. So what?
The point is we have to make certain assumptions to get anything done. Without them we can't have science, we can't have ethics. We'd be all alone with our own thoughts. This is the same problem Descartes struggled with as well. He had so effectively doubted everything that he concluded that he could only know one thing with 100% certainty, that is, that he existed. All other possibilities are merely probable and require certain assumptions. I therefore hold that it is inconsistent to be relativistic about morality but not about empiricism (and by extension most of rationality).
A couple of years back I stumbled across this diagram on reddit. Since then I've kept a list of all illogical arguments, quackery, irrational ideas and similar nonsense, to pass the time. The count as of today stands at 1229 irrational ideas (a few could be debated perhaps). Hopefully you'll have a laugh or two! Any additions let me know!
Link to the list:
https://docs.google.com/spreadsheets/d/1T3HQ6TnCg6Q44WzpJPFxLvfqbfvKmT5RqvpGI3ji1y8/edit?usp=sharing
And the original diagram: