Study math! Noone will be able to fool you.
People do stupid things because someone told them to do soo. People listen to 'experts' because they don't trust their own opinion. Mathematics will teach you to think, state problems clearly, find and assess the evidence, understand the principles, and decide wisely. Bernard Baruch noticed this:
"Millions saw the apple fall, but Newton asked why."
John von Neumann, the most famous mathematician of the 20 century, adds:
"If people do not believe that mathematics is simple, it is only because they do not realize how complicated life is."