How to study a very difficult subject?

Suppose you are a student in professional school like Polytechnic ,Engineering college or Medical college or any discipline- It is very easy to study.The only thing what you have to do is that

1. First you close the book.
2. Then go out and have a cup of tea and return back within 10-15 minutes.
3. Then take some bakery items in a saucer and eat and study very slowly.
4. Then you feel some easiness in study.
5. Take time to study.

When you obey the above rules,it is very easy to cope up with difficult situation.