I got my first cat (B) after I found myself alone after a break-up.  Having never lived by myself, coming home to an empty house was pretty depressing.  I had no idea the difference it would make, but the change was instant.  There was always someone home and she was happy to see me, even if it was verbalized in the form of incessant meowing.  Henri (when I have him), Hank, and B may not be kids, but they are loved.  They make a house a home and a couple of people – a family.