What a touching article. I'd never head of the "imposter syndrome" but I do feel related. As Jeff mentions, we shouldn't try to fix that feeling, although it is an uncomfortable one at times. I think it helps one to stay humble.
It often happens people in the organization come to me in order to solve a problem that is not really my domain. For example, asking me guidance on indexes and tuning a query, while I consider myself more of an infrastructure DBA, installing and configuring SQL. But, these people know me as "the DBA" and they rely on me to help them. Even though I tell them that tuning is not my expertise but that I'll be glad to help if I can, it feels like I'm kind of betraying myself as well. Do I know enough to answer their questions? What if I hand them the wrong information and performance even degrades? I start Googling, reading articles, testing. I find all kinds of interesting information from Paul R, Brent O, Jeff M, Paul W, Glenn B, Kimberly T, Aaron B... I can go on :). And I try to learn something, pick things out, summarize... and hand them over the info, hoping it'll be OK. But I never feel 100% satisfied nor comfortable.
I don't like people addressing me as "the guru", "the expert"... (I really don't), because I know I'm not. Not just talking about SQL, but friends asking me to have a look at their computer for all kinds of issues, because, well, "you work in IT" :). I always respond "it just looks to you like I'm an expert, because we have different jobs and skills". I couldn't do my friend's work. He's a carpenter. I picture myself struggling with my keyboard with only 3 fingers 🙂
I love learning new stuff or getting a deeper understanding of things I already (think I) know. And I like to share that knowledge. I always wanted to own a blog but then the imposter-syndrome kicks in. Because, who am I to tell others how to do things? There are a lot of smart people out there that know a lot better. And I thank them every day for writing those articles and responding to questions in forums. I learned a lot from them. Respect.
Btw I just tried to answer a few questions on QOTD. Well, that didn't help getting the imposter-feeling out of the way :). But again, I learned a few things.