Maple

“Toska - noun /ˈtō-skə/ - Russian word roughly translated as sadness, melancholia, lugubriousness.

"No single word in English renders all the shades of toska. At its deepest and most painful, it is a sensation of great spiritual anguish, often without any specific cause. At less morbid levels it is a dull ache of the soul, a longing with nothing to long for, a sick pining, a vague restlessness, mental throes, yearning. In particular cases it may be the desire for somebody of something specific, nostalgia, love-sickness. At the lowest level it grades into ennui, boredom.”
― Vladimir Nabokov

“…There are times when something is asked of us, and we find we must do it. There is no calculation involved, no measure of the necessity of the thing itself, the action that must be performed. There is simply an acknowledgment that we will do the thing in question, and then the thing is done, often at considerable personal cost. "

"What goes into these decisions? What tiny factors, invisible, in the jutting edges of personality and circumstance, contribute to this inevitability?”
― Jesse Ball, The Curfew

“It eluded us then, but that’s no matter—tomorrow we will run faster, stretch out our arms farther. . . . And then one fine morning—
So we beat on, boats against the current, borne back ceaselessly into the past.”
― F. Scott Fitzgerald, The Great Gatsby

“Everyone seems to have a clear idea of how other people should lead their lives, but none about his or her own.”
― Paulo Coelho, The Alchemist