The Lie of Physics

I have been believing in a lie for almost 3 years from now, since that immemorable date during my third year in high school --- when the concepts of circular motion were introduced for our Basic Physics class.

So, here's the truth, according to my current General Physics lecture (PS14) teacher:

There is no such thing as centrifugal force.

This just made me think, "Why is it in the book, then?"