Someone who's on top of the world isn't much of an observer: happy people are poor psychologists. But someone who's troubled about something is on the alert. The perceived threat sharpens his senses - he takes in more than he usually does. The Post Office Girl 

What is love? For the rabble love is a kind of variety, a transient vulgarity; the rabble's conception of love is best found in their obscene ditties, in prostitution and in the foul idioms they use when they are halfway sober, such as "shoving the donkey's foreleg in mud," or "putting dust on the head." My love for her, however, was of a totally different kind. I knew her from ancient times—strange slanted eyes, a narrow, half-open mouth, a subdued quiet voice. She was the embodiment of all my distant, painful memories among which I sought what I was deprived of, what belonged to me but somehow I was denied. Was I deprived forever? The Blind Owl

I wonder whether any other generation has seen such astounding revolutions of data and values as those through which we have lived. Scarcely anything material or established which I was brought up to believe was permanent and vital, has lasted. Everything I was sure or taught to be sure was impossible, has happened. Never Give In!

“And how can I fly if we are holding hands? And what good is it for us to both fly away? And besides – this is actually the main thought of the above – I’ll never go so far away from you again.” (31 July 1920) Letters To Milena