How we cite our quotes:
Quote #1
Maman died today. Or yesterday maybe, I don’t know. I got a telegram from the home: "Mother deceased. Funeral tomorrow. Faithfully yours." That doesn’t mean anything. Maybe it was yesterday. (1.1.1)
The opening sentences of the novel embodies Meursault’s absurdist outlook on life, his emotional indifference and detachment to people, and his passive but quiet alienation from the rest of society. It’s also a big flashing clue that our protagonist is unaware and apathetic. He doesn’t even know which day his mother died, and to him, it "doesn’t mean anything" anyway.
Quote #2
[A] soldier […] smiled at me and asked if I’d been traveling long. I said, "Yes," just so I wouldn’t have to say anything else. (1.1.4)
Super typical of his particular brand of passivity and/or detachment (i.e., Absurdism), Meursault does something just so he won’t have to do something else.
Quote #3
That’s when Maman’s friends came in. There were about ten in all, and they floated into the blinding light without a sound. They sat down without a single chair creaking. I saw them more clearly than I had ever seen anyone […]. But I couldn’t hear them, and it was hard for me to believe they really existed. (1.1.15)
Meursault is content being a spectator in life, and may even be slightly solipsistic. (Solipsism is the belief that yourself is the only thing you can truly know exists—you know you’re not a figment of the imagination... but you can’t say the same for everyone else around you.) If this is true, it explains why he finds it difficult to sympathize or empathize in any way.