The Search For "Happiness"

Happiness is kind of feeling which we experience in different shapes. So, it's not about when you should but the feeling is an automatic response of certain emotions. You cannot resist it. Being happy is simply a sense of satisfaction, the pleasant feeling that one gets when a pleasant event occurs.
This event could be anything, spending time with loved ones, completing a work or project successfully, winning at a competition or at sports,.
mostly the process remains in your thoughts.

 the art is to keep your mind clear and enjoy the moment

When we are truly happy, we do not think. We simply enjoy the moment  ... 
Perhaps there lies the secret of True Happiness ... embrace the moment fully. Be open to whatever it brings.

My own experience brought out another aspect of Happiness .....

Most of the time I am happy. I've great acceptance of whatever comes around. I always see the good in anything and be happy. I know it's for my best interest.
I don't usually share anything, be it happiness or sadness. Sometimes I feel sad when I am disappointed but then I know it will be okay.
When I do share happiness, it's usually passing it along, if I'm happy I try and make others happy by doing something unusual for them. When I'm not happy, I still do it as their happiness brings me happiness. And When I am the reason for someone's happiness brings me a deep satisfaction! 
Well, small little efforts can easily play an effective role in bringing happiness to someone's life and making them smile.
I'm always at peace. And when I'm not, I correct myself to be that way.
I feel happy when a thing happens in my favor or to people in my circle. If the thing is confined to me I will be over excited and will say to everyone I found in the way. If thing occurred to people in my circle I would say it " I'm happy for you". 
Yes, we need to share the happiness because anxiety calms down when we share our feelings with someone else. I would simply share with my close friends or my family when I am happy.

You feel happy when you don't' think about anything else, and just enjoy the moment. You feel happy when someone makes you proud, when you achieve your goals, when you have a kiss for the first time, when you get something free of cost, when someone listens to you when you are in trouble, etc etc..
See there is no as such a particular stage/event in which everyone feels happy.
Happiness is  different for different people ( of different age)

For example: A kid of age around 8 will feel happy if his mother allows him to play all the time in fields/ allow him to play games on computer/mobile/PlayStation.
whereas a young person of age around 25 will feel happy when he/she gets his/her dream job.

So, happiness is about something you enjoys to do, something is waiting for a long time or something you do every day. 
Basically, happiness varies from person to person. There are some people who can manage to be happy even when they are in problems, and there are some who are always involved in some sort of problem and forgets how to be happy.

Now how to express your happiness... 
Smile, Shout, Laugh, Jump, Dance, Dive or just sit in a quiet place contemplating over the reason for your happiness, whatever makes you grin.
Just don't let your happiness make way for anyone else's gloom, because that happiness will be shortlived. Live in the present, don't ponder too much over past and sure as hell don't worry about the future.