In The Book of Awakening, author Mark Nepo tells a story of an aging Hindu master and his apprentice who was doing a lot of complaining. He had the apprentice taste a handful of salt in a glass, then the same amount of salt in a lake. It went from bitter to fresh. So the master sat beside him and said:

The pain of life is pure salt; no more, no less. The amount of pain in life remains the same, exactly the same. But the amount of bitterness we taste depends on the countainer we put the pain in. So when you are in pain, the only thing you can do is to enlarge your sense of things … Stop being a glass. Become a lake.