Suppose a man plants a tree hoping that one day he would rest under the tree, eating fruits along with his wife and kids. He tells himself:- I'll be very happy that day.
Now, once he tells himself that he "WILL" be happy, his happiness gets postponed. Now every time he seeks pleasure in some other thing, he starts wishing- "Had my plant grown by now, I would have seated in its shade and enjoy this ever more."
After days and days spent waiting for that specific day, there are fleeting moments of love, affection and happiness that he misses out.
Now one day, he is finally sitting under that tree, eating fruits with his wife and child. His dream has come true. But this time if his children misbehave with him, his dream setup will cripple and he'll mourn why is his special moment being ruined? Therefore his long term goal didn't bring about happiness. The tree brought comfort and fruits. When kids misbehaved, man was still seated with comfort under the tree. But whether that comfort brings happiness or not, that comes from the heart of the person.
Human being strives to perfection, and perfection does not exist. Therefore one who wants to be happy should give up on his drive for perfection. Perfect setting doesn't bring about happiness
Instead of delaying his happiness, if that man had thought that, together, I and my family sow the seed, let us celebrate together. Then, when the seedling originates, he should be happy. And finally when tree would grow, he must seek pleasure that it has grown.
Happiness isn't mechanical, generally its aspects are:- physical(first), emotional(second) and spiritual(third) in that order of relevance.
A person should set his agenda, his goals because they give comfort. Happiness is what person gives to himself.
Therefore grow a tree, (it's an environmental bliss), sit under it, enjoy fruits but don't delay your happiness. Goals of life should facilitate happiness, should not refrain man from being happy till that goal completes. Happiness like every other wonderful things in the world, come in small packages. They are floating around you. Grab them and have fun