Welcome to Derry May Have Unraveled a Longstanding It Mystery
Pennywise's influence on the children of the Derry series shapes them throughout their adult lives, transforming them into the very adults who perpetuate the community's cycle of animosity alive. The creature preys most easily on children from fractured homes — youngsters who frequently grow up to replicate the same patterns as their parents. However, the Hanlon family stands apart as one of the few family unit that never splinters, which could clarify why Mike Hanlon, even after choosing to stay in the town, remains the only Loser who doesn't completely succumb under the clown's influence.
Hanlon Household's Unique Resilience
In episode 4 of Welcome to Derry, Leroy at last grows increasingly conscious of the supernatural forces enveloping the community, especially when the entity starts haunting his child, Will Hanlon, during their fishing trip. The Hanlon family consists of some of the few grown-ups who are cognizant that things are not right with the municipality, especially the father, who was revealed to be sensitive to psychic abilities when he was able to detect a fellow psychic's use of it in the third episode. Subsequently, he spots one of the clown's trademark inflated orbs outside his residence. The ability, alongside his inability to experience terror, combined with the foundation of his household, may be why he's capable of perceiving Pennywise's hauntings. However, consider if that shining is hereditary, and a key factor Mike is among the few adults in Derry who didn't lose themselves to its cruelty?
Will is part of the group of children at his educational institution being terrorized by Pennywise. His classmates hail from dysfunctional families, with parents who refuse to accept they're being haunted. The reason Will is being haunted is due to the cruelty of the town, combined with his potential sensitivity to shine, which makes him susceptible. This family are fundamentally strangers in Derry during the early sixties, which lends itself towards the household sensing anomalies exist about the locality from the onset. They also have a good foundation that isn't fractured, in contrast to the folks who originate in the town, with relationships that have deteriorated within.
Historical Context
Based on the original book, we know the young Will Hanlon will end up at the Black Spot, where the psychic will save him from a blaze that the town bigots of the community will ignite. In the recent movie, we see that Will has a boy named Mike and that the father ultimately dies in a configration, with his father outliving his own child and taking his grandson in. The public account in the film is that the parents were on drugs, but given our current view of Will in the series, that's hard to believe. Perhaps the shy boy, once he grew up, leaned into alcohol to rid himself of the hauntings, or maybe the rotten town affected him first, with the hate group eventually finishing the job it started long before. Whether through the terror of the entity or via the malice of the town, seeded by Pennywise, the creature in the end achieves the last laugh on him.
The Father's Evolution
These occurrences would explain how the elder Hanlon transforms so drastically from what we see in It: Chapter 1 and the prequel. In his later years, Leroy seems resentful and much stricter with his parenting. Because he survived his own offspring, it's understandable to see such a profound shift. However, his words hold greater significance now that we know he's seen the clown's activities and the impacts they wrought upon his son. In the initial sequence of the movie, we see Mike pause to use a bolt gun on a animal at the family property. His grandfather reprimands him for hesitating and offers an analogy that leads to a survival-of-the-fittest scenario.
“You have two options you can be in this existence. You can be out here like we are, or you can be in there,” Leroy says as he points to the creature. “You dawdle indecisive, and another is going to decide for you. But you won't know it until you experience that bolt in your head.”
Looking back, this could be a piece of foreshadowing, something he regrets not imparting to his own son. Maybe he wishes he had done something in his past, but for certain factors, he couldn't resist the sickening attraction of Derry.