I can relate to this. I wonder if forums like HN exacerbate it -- here, someone is always an expert on whatever you're talking about, just by the sheer volume of folks who come here. So it sometimes seems like everyone is a published expert with a sweet funded startup using Haskell and Go and algorithms I can't comprehend, fending off offers from Google and Facebook.
It's easy to forget that there are a lot of programmers diddling with enterprise java and php on a day to day basis, not doing anything particularly mind-blowing, just dutifully closing their tickets.
This. And we also do it to ourselves when looking for work, exacerbating the problem and pushing onto future IT personnel. Just look at the job descriptions for most IT jobs out there and you'll see that IT personnel are expected to know way too much, when really you just need the fundamentals (everything else can be learned just-in-time). I've written a much longer answer detailing a specific job description that helps flare up my imposter syndrome: http://typicalrunt.me/2013/07/29/a-response-to-crushing-the-...
It's easy to forget that there are a lot of programmers diddling with enterprise java and php on a day to day basis, not doing anything particularly mind-blowing, just dutifully closing their tickets.