Math is not hard if your mind is set to learn and master it. I strongly believe that the psychological aspect of a learner is one of the biggest factors why many consider it as a difficult field of study. There are two laws that I personally think should be considered by Math teachers in teaching the subject.

First is the Law of Learning by Thorndike. There are actually three laws of learning: Readiness, Exercise, and Effect. Readiness is crucial in teaching Mathematics, or any subject. Under this law, motivation is essential to achieve learning. People learn best when they are physically, mentally, and emotionally ready to learn. On the other hand, they do not learn if they do not see any reason for learning. Perhaps this is the reason why Math is my waterloo. I can't find valuable reasons in learning algebra, trigonometry, or any other fields of Mathematics that may be useful or at least applicable in my daily life. That's why I always felt sleepy (sometimes dizzy) in every Math class I've had back when I was still studying. :D

The second one is not actually a law but a theory - the Theory of Multiple Intelligences by Gardner. This theory states that every individual has his own field of inclination or expertise based on his skills and abilities. Those who excel in Math have the Logical-Mathematical intelligence. In my case, I'm interested with words and languages therefore I have a Verbal-Linguistic intelligence.

However, it is not impossible for an individual to possess more than one intelligence. These are the people whom we can consider as gifted or genius individuals. Chances are rare though.

This is only my personal opinion and based on my own experience as a learner. I hope I could be of help. :)