I think it mostly comes down to two camps, those who create an internet persona primarily associated with things they like, vs. those who create an internet persona primarily to dissociate from themselves. This isn't a perfect explanation, but it's a pretty good generalization, I think.
If you're in camp one, I'd say you're far less likely to be affected by your internet presence, because it's mostly an extension of things that are already you, simply written under an alias, which isn't really anything new. Camp two, however, is more akin to being an actor and playing the same character on the same show for years on end, wherein there's a disconnect in how you have to act that will, eventually and gradually, both level out somewhere in the middle, depending on which half of you is the more "temporally dominant" so-to-speak.
In general, I think the concept of "act differently in different situations" is pretty easy for people to grasp, i.e. the difference in conduct between a party and your workplace could be considered different "personas," but they more than likely are both extensions of your alone-self's desires and personality. The concept of "be a whole different person entirely and then go back to myself" is, well, significantly harder to grasp, when you have to remodel an entire thought process separate from your own, it's natural that the messy meat-computer we run on would integrate some of those thought patterns into your "base" self.