It is not necessary that you should memorise by heart.
The easiest way is: If you want to remember a thing, you must for get it
five times. The number five will vary from person to person. If you want to
remember and essay of twenty lines; read it slowly once. The next day
you read again; the entire essay will be new. On the third day, you will remember
most part of it. On the fourth day, you can reproduce the entire essay!
Maximum is five times. Please try it.