Welcome to Derry Could Have Solved a Longstanding Pennywise Enigma
Pennywise's influence on the children of the Derry series molds them long into adulthood, transforming them into the exact individuals who keep the town's cycle of hatred alive. The creature preys most easily on kids from fractured households — children who frequently mature to replicate the identical behaviors as their guardians. But, the Hanlon household stands apart as one of the few family unit that never splinters, which could clarify why Mike Hanlon, even after electing to remain in the town, remains the sole member who never fully falls under the clown's influence.
The Hanlon Family's Unique Resilience
In episode 4 of Welcome to Derry, Leroy Hanlon at last grows more aware of the supernatural forces surrounding the neighborhood, especially when the entity starts haunting his son, Will Hanlon, during their fishing trip. The Hanlon family consists of some of the few adults who are cognizant that something is amiss with the town, notably Leroy, who was revealed to be receptive to the Shining when he was able to detect Dick Hallorann's use of it in episode 3. Later, Leroy sees one of Pennywise's signature balloons outside his residence. The ability, alongside his inability to feel fear, combined with the foundation of his household, could be why he's able to see Pennywise's hauntings. But what if that shining is hereditary, and a key factor Mike Hanlon is among the few adults in Derry who didn't lose themselves to the town's malevolence?
Will is part of the collective of children at his educational institution being terrorized by Pennywise. All his school friends hail from dysfunctional families, with caregivers who don't believe they're being targeted. The reason he is being haunted is due to the viciousness of the town, combined with his likely receptiveness to psychic abilities, which makes him susceptible. This family are fundamentally outsiders in Derry during 1962, which lends itself towards the family feeling anomalies exist about the locality from the onset. Additionally, they possess a good foundation that isn't fractured, in contrast to the residents who come from the town, with bonds that have deteriorated internally.
Historical Context
Drawing from the It novel, we understand the juvenile Will Hanlon will find himself at the infamous nightclub, where Hallorann will save him from a fire that the local KKK members of Derry will cause. In the 2017 film, we observe that Will has a son named Mike and that Will ultimately dies in a configration, with his father surviving his own son and adopting his grandchild. The official story in the motion picture is that Mike's parents were on substances, but given our current view of Will in the series, that's hard to believe. Maybe the timid youth, once he grew up, leaned into drink to free himself of the torments, or maybe the rotten environment got to him initially, with the hate group eventually completing the job it began long before. Be it via the fear of the entity or through the cruelty of the town, seeded by Pennywise, It in the end achieves the last laugh on him.
The Father's Evolution
This chain of events would explain how Leroy changes so drastically from what we witness in It: Chapter 1 and the prequel. In his later years, Leroy appears resentful and much stricter with his parenting. Because he outlived his own son, it's comprehensible to see such a profound shift. However, his statements carry more weight since we are aware he's witnessed Pennywise's hauntings and the impacts they wrought upon his child. In the initial sequence of the movie, we observe Mike hesitate to use a stunning device on a sheep at the family property. His grandfather reprimands him for delaying and provides an metaphor that results in a kill-or-be-killed situation.
“There are two places you can be in this world. You can be out here like us, or you can be in there,” Leroy says as he points to the sheep. “You dawdle hemming and hawing, and someone is going to decide for you. But you will be unaware it until you experience that projectile between your eyes.”
Looking back, this could represent a piece of foreshadowing, a lesson he wishes he had told his own son. Maybe he desires he had acted differently in his past, but for certain factors, he couldn't resist the sickening attraction of Derry.