Welcome to Derry Could Have Solved a Longstanding Pennywise Mystery
Pennywise's influence on the young residents of Welcome to Derry molds them throughout their adult lives, twisting them into the very adults who perpetuate the community's pattern of animosity ongoing. It preys most easily on kids from broken households — youngsters who frequently mature to replicate the same patterns as their parents. However, the Hanlon household stands apart as a rare example of a family unit that never splinters, which may explain why Mike Hanlon, even after choosing to stay in the town, persists as 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 finally becomes increasingly conscious of the supernatural forces enveloping the community, particularly when the entity starts haunting his son, Will, during their fishing trip. The Hanlon family consists of a small number of adults who are aware that something is amiss with the town, especially Leroy, who was revealed to be sensitive to the Shining when he was able to detect a fellow psychic's employment of it in the third episode. Later, Leroy sees one of the clown's trademark balloons outside his house. This gift, alongside his failure to experience terror, along with the foundation of his family, may be why he's capable of perceiving the entity's manifestations. However, consider if that shining is hereditary, and one of the reasons Mike is among the few adults in Derry who resisted succumbing to the town's malevolence?
Will is part of the collective of children at his educational institution being terrorized by the clown. His classmates come from dysfunctional families, with parents who don't believe they're being targeted. The reason Will is being haunted is because of the viciousness of the community, paired with his likely receptiveness to psychic abilities, which renders him vulnerable. The Hanlons are fundamentally strangers in Derry during the early sixties, which lends itself towards the household sensing anomalies exist about the locality from the beginning. Additionally, they possess a good foundation that isn't fractured, in contrast to the folks who originate in the area, with relationships that have decayed within.
Historical Context
Based on the original book, we know the young Will will end up at the infamous nightclub, where Hallorann will rescue him from a blaze that the local KKK members of Derry will cause. In the 2017 film, we see that he has a son named Mike and that the father ultimately dies in a configration, with his father outliving his own child and taking his grandson in. The official story in the film is that Mike's parents were on substances, but given our current view of Will in Welcome to Derry, that's difficult to accept. Maybe the timid boy, once he became an adult, turned to alcohol to rid himself of the torments, or perhaps the rotten town affected him first, with the hate group eventually completing the job it began long before. Be it via the terror of Pennywise or via the cruelty of the town, instigated by It, It in the end achieves the final victory on him.
The Father's Evolution
This chain of events would clarify how Leroy transforms so drastically from what we see in the first film and Welcome to Derry. In his later years, Leroy seems resentful and much stricter with his parenting. Because he survived his own son, it's comprehensible to observe such a drastic change. However, his words carry more weight now that we know he's witnessed Pennywise's hauntings and the impacts they wrought upon his son. In the opening scene of the movie, we see the boy hesitate to use a stunning device on a sheep at Leroy's farm. Leroy chastises him for hesitating and provides an metaphor that leads to a survival-of-the-fittest scenario.
“You have two options you can be in this world. You can be in the open like us, or you can be trapped inside,” Leroy says as he points to the creature. “You dawdle indecisive, and another is going to decide for you. Except you won't know it until you experience that projectile in your head.”
In hindsight, this could represent a bit of prediction, something he regrets not imparting to his own son. Maybe he wishes he had done something in his past, but for certain factors, he was unable to avoid the sickening allure of Derry.