There's a difference in expectation I've noticed between when a blogger comments on something I've written here and when a family member or blogless friend does so.
We bloggers rarely break the fourth wall with each other.
I might go on someone's blog and completely word vomit my deepest beliefs about religion and politics, but the next time I see her, it's like it never happened. She knows what I wrote; I know she knows what I wrote, but to acknowledge it might disturb the fragile belief that what we write is going out to some nameless, faceless audience in the ether and not actual people sitting at their laptops in front of Saturday Night Live reruns.
It's sort of terrifying to think about the real people, because they might someday walk up to you and confront you personally with what you've written, and then you'll be forced to acknowledge that those were real people the entire time.