The quick answer is a resounding NO!
Age is not related to happiness because happiness has nothing to do with being a specific age.
What happiness does have to do with are the following 3 life circumstances:
- enthusiasm about life and living
- minimizing depression
- being healthy
And these three circumstances are interrelated.
Enthusiasm is that child-like quality of wonder or passionate interest in life which, sadly, we seem to let diminish as we age. Henry David Thoreau once remarked: “None are so old as those who have outlived enthusiasm.”
Enthusiasm is seeing each new day and each new moment as a gift – a wondrous event; one that has such potential that we can be awe struck.
Remember when your child was a baby? Everything was new and fun. Your child sat and stared at a flower, the cat or dog, or at you! And I bet you spent hours watching your baby sleep.
Your young child was engrossed for hours pulling the petals off roses – smelling them or eating them. Ditto the dandelions and grass. Or listening to you read the same story over and over and over as if it had never been heard before.
What happens that as we age we lose much of our enthusiasm? Many think it’s our education system and/or the current state of stress in modern families. Children just don’t seem to be allowed to spend those hours with the roses or with the parent reading – everyone is just too busy to allow it to unfold like that.
But even for children who can stay enthused by the world around them, the prevalent culture of TV and school soon start to diminish this.
Minimizing depression
Maybe losing our enthusiasm as we age increases the incidence of depression? If each day brings wonder and excitement – it’s hard to be depressed. You get out of bed eager to see what the day has in store. You walk, you meet with friends, you go to work or you sit happily by yourself thinking about what a great thing it is that you are alive and happy about all that you can do!
Being healthy
If you are healthy it is easier to be enthusiastic and to minimize depression. But it works the other way too. If you are enthused and have minimal depression – you do things that make and keep you healthy.
We live in a wonderfully and intricately interconnected body and mind.
Stop and think why we label this phenomenon of enthusiasm as “child-like enthusiasm.” I never hear “adolescent-like enthusiasm” or “adult-like enthusiasm” as if these are not possibilities.
Go and find that 
enthusiasm you had way back when and don’t worry if others say you are acting “like a child.”
Stop and smell those roses!
It will help you grow older better.
WONDERFUL post! Thank you.