Secret of learning even toughest things revealed. How to learn the toughest things.?

Today I experienced and discovered a great secret, what things we feel most easier to learn instead they might be the toughest things to learn and what things we feel most tough even though they may be most easiest things.

The answer to the above staement is much easy and can be described in one word that is

                     INTEREST

Very true. If you have interest in most tough topics as you may be a genius, you will feel it most easy and if you have no interest then it may be most toughest thing to learn. So the solution to all these kind of problems is just interest.