secret of happiness

I read a line as the following:
"The secret of happiness is the realization that life is a gift, not a right."
The writer keeps telling us that Once we understand this axiom of life, our perspective on everything changes. And once our perspective on everything changes we become more fulfilled. And once this happens, we become much happier and realize that our life is different than it was before.

Well, I agree with the writer. Of course, if we think life is a gift, then we will cherish it, at least, most people will cherish gifts since gifts are seldom. If we think life is a right, then we will often think other people or God owe us and we will be disappointed and frustrated.  But what about the difficulty and trouble in life. Do we think difficulty and trouble a gift ?
so, I modify the line as
"The secret of happiness is the realization that life is a gift and the God will eventually take it away." Once we realize that life is only a gift that the God lease to us, we will cherish it more. If you own a book, you may never open the book. If you borrow a book, you will read quickly. That is life. 
Don't let the difficulty and trouble burden us ! Faces it with a smile and overcome it!
Life is short, so enjoy it!