Do not grieve over any joy that has gone forever, for it will return to you in another form, know that for sure.
Don't grieve for what doesn't come. Some things that don't happen keep disasters from happening.
Beauty surrounds us, but usually we need to be walking in a garden to know it. RUMI, attributed, Conquest of Abundance: A Tale of Abstraction Versus the Richness of Being Don't grieve. Anything you lose comes round in another form.
Every fragile beauty, every perfect forgotten sentence, you grieve their going away, but that is not how it is. Where they come from never goes dry. It is an always flowing spring.