Tenzin Gyatso, 14th Dalai Lama Quote
If a problem is fixable, if a situation is such that you can do something about it, then there is no need to worry. If it's not fixable, then there is no help in worrying. There is no benefit in worrying whatsoever.
Policy of Kindness: An Anthology of Writings by and about the Dalai Lama (ed. Shambhala, 1990) - ISBN: 9781559397698