That perception is precisely what this study guide is trying to change. Mathematics is a logically connected web of facts and concepts and the most important thing is to understand the connections.
Once you do that you can move around in the subject, use your own judgment, recover from errors, decide for yourself what needs to be done, and solve more difficult problems. In the long run, understanding the principles is also more efficient than memorizing formulas and recipes.
Fine print, your comments, more links, Peter Alfeld, PA1UM