Watchfulness.

Happiness or sorrow –
Whatever befalls you,
Walk on
Untouched, unattached.

Happiness will come and sorrow will come. These are the seeds you have sown down the ages, and whatsoever you have sown you will have to reap. So don`t be disturbed. If happiness comes , don`t become too much excited; if sorrow comes, don`t become too much depressed. Take things easily.
Happiness and sorrow are separate from you; remain unidentified. That`s what Buddha means, “Walk on untouched, unattached” – as if they are not happening to you but happening to somebody else.
Just try this small device – it is a valuable recipe – as if they are not happening to you but to somebody else, maybe to character in a novel or in a movie – and you are just an onlooker. Yes, unhappiness is there, happiness is there, but it is there and you are here.
Don`t become identified. Don`t say, “I am unhappy.” Simply say, “I am the watcher. Unhappiness is thre, happiness is there. I am simply the watcher.”

Quoted by The Dhammapada: The Way of Buddha, Osho