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-...