“I remember the first day I had my first subscriber on my newsletter and I knew I guess I'm gonna do this forever now because this person wants to read my stuff”

Treat the first subscriber as a contract

The first real subscriber is an onboarding moment for the creator as much as for the reader — it converts "I might do this" into "I owe someone this." Design the confirmation step to make that contract explicit: name the cadence, the format, what they get. The psychological weight of that first opt-in is what produces consistency for the next 100 issues.