It is just like we have a plate full of food and you need to only get your hands on it to have it and enjoy the taste of that delicious food. So just dig out in your life and the happiness is all yours for lifetime.
The same condition can give us happiness to you and the same condition may give other sadness. So it is the approach of an individual for the happiness.
So it is important to simply be happy in any damn situation and then nothing can make you sad for sure.