Is humor necessary?

Why did people say that laugh is very important? Experts have done a lot of experiments about people's humor, they have seen as a result that happy people live more years than sad people. Moreover people with any types of illnesses get better faster if they accept their health situation  and they want to overcome this with happiness.
We must take life with positivism, we will be happier and our health will impruve.

First of all you must be happy with your self, then when you feel confident you must make friends. People with friends are allways happier. You begain to be positive so other people will like to be with you and they will rise their positivism too.
To have funny moments you can watch funny videos or films, go party with friends, telling jokes,...

As a result I think that people with a funny life is happier that sad people and that we all must try to laugh minimum one time a day.
However there is only one life and it is not worthit to spend our life having concerns!