How we cite our quotes:
It occurred to me that anyway one more Sunday was over that Maman was buried now, that I was going back to work, and that, really, nothing had changed. (1.2.11)
Meursault was isolated from his mother both before and after her death; this is why "nothing [has] changed."
[…] he asked me again if I wanted to be pals. I said it was fine with me: he seemed pleased. (1.3.7)
Here we see that Meursault doesn’t pursue isolation; it’s just that it is usually the path of least resistance for him. When the easiest road is friendship, then he takes that one instead.
She was wearing a pair of my pajamas with the sleeves rolled up. When she laughed I wanted her again. A minute later she asked me if I loved her. I told her it didn't mean anything but that I didn't think so. She looked sad. But as we were fixing lunch, and for no apparent reason, she laughed in such a way that I kissed her. (1.4.3)
Meursault is isolated even from the one woman in his life.