Pseudoscience is a claim, belief or practice which is falsely presented as scientific, but does not adhere to a valid scientific method, cannot be reliably tested, or otherwise lacks scientific status. -Wikipedia

So in essence pseudoscience is any idea that is completely or partially invalid (i.e has no basis in reality), and that is portrayed as non fiction. Usually an idea made to fool you into thinking it's real, but is in fact just a hoax. This includes everything from astrology to detoxes and bigfoot.

So like I said, chances are you've been had, and didn't even realize it.

And so for anyone who does not enjoy being a fool it is naturally of great importance to be able to tell whether something is valid or not.

Most forms of pseudoscience can be dismissed as silly but nonetheless harmless delusions. However many forms of pseudoscience can be very dangerous. ...[Continue reading on Scientific Literacy Matters]