I identify with the meaning given to "nostalgia" by Tarkovsky, which in one Russian sense means a longing for one's home so sweet and sharp one might almost leave home in order to feel it..... I've never understood this bittersweet narcissism within myself. I love to wander lonely streets in unknown cities. To find a cafe and order a coffee and think to myself -- here I am, known to no one, drinking my coffee and reading my paper. To sit somewhere just barely out of the rain, and declare that my fortress. I think of myself in the third person: Who is he? What is his mystery? I have explained before how I'm attracted to anonymous formica restaurants where I can read my book and look forward to rice pudding for desert. To leave that warm place and enter the dark city is a strange pleasure. Nostalgia perhaps. 

--Roger Ebert; from All the Lonely People 

(thanks to Quiet Bubble)