…at night, if I succeeded in going to sleep, then it was as though the memory of Albertine had been the drug that had procured my sleep, whereas the cessation of its influence would awaken me. I thought all the time of Albertine while I was asleep. It was a special sleep of her own that she gave me, and one in which, moreover, I should no longer have been at liberty, as when awake, to think of other things. Sleep and the memory of her were the two substances which I must mix together and take at one draught in order to put myself to sleep.
—Marcel Proust, In Search of Lost Time