How do we know if that is true?

Because right now nootropics (pills that make you smarter) don't actually work and performance enhancing drugs shorten your lifespan and damage your health in various different ways. Furthermore based on the way drug discovery goes you're not likely to go off and invent a safe and effective version of either of those.

That means that for now, a philosophically resigned stance combined if you're contributing to research with curiosity to motivate you rather than an expectation of any results, is the most appropriate stance as far as anyone knows.