
There is an old story from the Buddhist tradition which illustrates this, here told by Thich Nhat Hahn:
One day the Buddha was sitting in the forest with some monks when a farmer approached them. The farmer said, "Venerable monks, did you see my cows come by? I have a dozen cows and they all ran away. On top of that I have five acres of sesame plants and this year the insects ate them all up. I think I am going to kill myself. It isn't possible to live like this"
The Buddha felt a lot of compassion toward the farmer. He said "My friend, I am sorry, we did not see your cows come this way". When the farmer had gone, the Buddha turned to his monks and said "My friends, Do you know why you are happy? Because you have no cows to lose"
I would like to say the same to you. If you have some cows you have to identify them. You think they are essential to your happiness, but if you practice deep looking, you will see that it is not these cows that have brought about your happiness. The secret of happiness is being able to let go of your cows.