Its not easy to understand anything without interest. Try building it first. Start from basics and carry on with problems daily. Try the problems first without looking at solutions. The 11th and 12th books provide a great start to calculus.
Learning calculus by memorizing tricks is probably the most difficult way to learn to understand calculus.
In short, calculus involves a variety of clever tricks for getting a solution with minimal work. However, when using these methods one should always have in the back of their mind their origin: the defintions such as that of the derivative, integral, or limit. Defintions in math are extremely important, so study them well. Also, make sure to have a solid understanding of algebra and trigonometry, and the graphs given by their functions.
A good introduction to calculus book is Calculus Made Easy by Thompson. But at some point, you should pick up a textbook and do as many problems as possible, then go back and study the theory a little deeper.
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