I love how you can slowly piece together the backstory of Kelly and how he became this way through the strips, with all the little details spread out.
We can first see that it's shown that Kelly's dad walked out on him at a young age- and it's hinted that his dad wasn't very good anyway, that he drank all day, as shown in the strip about modern day fathers. After his dad walked out, Kelly was forced to work during the summer selling newspapers and other menial jobs, gaining a jaded view of the modern world, as well as trying to convince himself that his father gave him the gift of man of the house, rather than just dumping his family.
Kelly then spent his next few years of adulthood trying to emulate his father- who he now thinks is the best role model to think of. He buys liquor, frequents strip clubs and porn shops, and unsuccessfully tries to pick up girls at a college campus. When Kelly did meet a woman, he got married to her thinking she would be the subservant housewife he believes her to be in some stereotype way.
But she starts talking about new ideas- getting job, working outside the house, maybe Kelly shouldn't drink so much. Their kids see their father as kind of a jerk, his constant demands and complaints, how he missed his daughter's recital or his son's game. Kelly, a few years into the marriage, runs off on a bus, and hides out in a hotel room. Of course, Kelly is located and is forced to get a proper divorce, leading to his anger about ex-wives and alimony checks.
Now free from marital status, Kelly now does what he does today- drawing comics of a world he wants to be, how he wants it to be. A Hooters that never closes. A beer store where he use as many discounts as he wants. Grocery stores have what he wants when he wants them. His children are portrayed as devils, haunting him with interventions on his drinking, bills, his ex wants alimony checks. Kelly is a man held together by a broken past held by nostalgia, and a man with a broken present.
