Spoilers for the newest episode!
Ah, December, that one month of the year when everyone was supposed to be joyful and excited for Christmas, or New Year's, or whatever holiday they celebrated.
Eh. Christmas had never really been Bob's favourite time of year, even when he was a child. He and Cecil had been told at a very young age that Santa Claus did not exist, so there was never much magic in the Christmas season as far as Bob was concerned. All of the emphasis on "family" and "joy" during the holiday season seemed to make a mockery of those who had little to no joy for the rest of the year, as well as having no friends or family with whom to celebrate. This festive season was supposed to bring out the best in people, but just as often, it brought out the worst in people. There was greed and commercialism, and people like Montgomery Burns, who just wanted to ruin other people's celebratory moods.
No wonder so many people attempted suicide at Christmastime.
The desolate surroundings of the lighthouse didn't help Bob's low mood very much. It certainly provided him with solitude, or at least a sense of solitude (that chatty Cassandra kept breaking his attempts at solitude and withdrawing from a world that seemed determined to put him down), but a small part of Bob still wanted companionship. Cassandra's comment about his lack of a wedding ring had stung him more than he let on; Bob had thrown his wedding ring into the sea when he finally accepted that Francesca would never return to him. One other reason Bob had accepted the Santa job was because of his long dormant desire to bring joy to children. He really was good with children, as long as they were not Simpson children. It was rather unfortunate that when Cassandra brought up the subject of children, the first child Bob thought of was Bart, instead of his own son. Bob remembered how Gino used to enjoy looking at big, bright Christmas trees, though his son had gotten cranky during midnight mass on Christmas Eve (Bob and Francesca hadn't really agreed on whether they should take him to mass when it was after his bedtime). Gino also hadn't much liked "Babbo Natale", as Santa was called in Italian; Gino would have pulled a fake Santa beard right off.
Bob could have strangled Bart with those Christmas lights when he had the reckless boy alone, but Hamlet was right: "Conscience doth make cowards of us all." Not even Bob's long-cherished fantasy of killing Bart made him feel any joy anymore. He'd gone soft, lost his ruthlessness, and his warped mind was always at war on whether this was a good thing or a bad thing.
Bob even found himself envying the Simpsons, of all the people to envy. Dysfunctional families seemed to come in two forms: those that simply hated each other, and those that still had love in them, even if it was very deep down. The Simpsons were the second kind of dysfunctional family, and Bob's family was the first kind. Against his better judgement (and probably against the Simpsons' better judgement as well, if they even had any good judgement), Bob had rode with the Simpsons back to Springfield after they caught Burns and his lackey stealing the packages. The Simpsons all sang that awful annoying Baby Shark song (well, except Maggie) and they all seemed to be enjoying themselves while singing it. Being a decent contortionist, Bob had been coiled on the floor, though he knew this wasn't the safest position to be in. Not only was he not secured by a seatbelt, Bob had to spend the journey trying to avoid Bart's kicking feet. The ungrateful brat never appreciated when Bob saved his life, or at least spared it; no wonder Bob's desire to kill him continued to resurface.
In Bob's childhood memories, everyone in his family always seemed to be doing something different: reading, rehearsing, working, etc. There was little unity, even when Bob tried to get his family to work together in that funeral scheme. His family hadn't even helped him when Homer threw hobo ashes in Bob's eyes, while Homer, Marge and Lisa had all worked together to save Bart's life.
Watching It's a Wonderful Life only twisted the knife further for Bob. He had no guardian angel to show him how he had positively affected people, if at all. No-one to pray for him when he was at his lowest point.
It was sort of nice for Bob to be able to spend Christmas night with Cassandra, however annoying she was most of the time (and despite the fact that she brought him a rake as a gift. Even if Bob hadn't possessed such a negative history with that garden tool from hell, a rake was still a rather stupid Christmas present). However, Bob still had that nagging feeling that this would only be a fling and not a meaningful relationship, and that Cassandra only liked the thrill of being with an attempted murderer.
Permanent happiness would always be out of Bob's reach. That seemed to be his lot in life.