How we cite our quotes:
I said that people never change their lives, that in any case one life was as good as another and that I wasn’t dissatisfied with mine here at all. (1.5.3)
For Meursault, being "not dissatisfied" is the same as being happy.
It was only after Marie’s first and last visit that it all started. From the day I got her letter (she told me she would no longer be allowed to come, because she wasn’t my wife), from that day on I felt that I was at home in my cell and that my life was coming to a standstill there. (2.2.1)
At this juncture in the book, Meursault is at a crossroads, transitioning from free man to caged man.
At that time, I often thought that if I had had to live in the trunk of a dead tree, with nothing to do but look up at the sky flowing overhead, little by little I would have gotten used to it. (2.2.10)
Meursault, because of his passivity, can be content in any circumstance.