When the night falls, the unnamed narrator finds it difficult to reign in his galloping thoughts.
Night for him means profound loneliness and also the only time when his thoughts and memories come back unbidden, often waking him up in the middle of the night.
His thoughts involuntarily go back his past, his country home in Combray and the people who once populated that time.
For a long time I used to go to bed early.
Sometimes, when I had put out my candle, my eyes would close so quickly that.