That's a good point. When something is within the usual for someone's experience, it's not going to be as obvious, so it becomes the baseline that's used to compare other things to. For stuff like religion, it's easy to assume that your amount is normal, and having more (if you don't feel like you have much) or less (if you do feel like you have a lot) is unusual.

I don't have any experience living outside of the northeast (although not New England specifically since high school), but I definitely agree that there's certainly more religion in New England than might be obvious from the outside (more Catholic than the rest of the country, which also might explain some of the differences).