>I don't understand how someone can "have enough experience and knowledge to not need the site".

If you've been programming for a couple of decades and you don't follow the trends du jour it's actually quite easy (note: I'm not at that level myself).

Seasoned C and C++ programmers, for example, don't have much to learn from Stack Overflow in the same way a (1) new programmer, (2) 0-20 years programmer who constantly juggles languages, APIs and frameworks etc depending on the job and the fads of the season.

You think someone like Linus checks SO to get his answers?

There are tons of programmers with such levels of experience (even if somewhat less so than Linus).

Let's put it another way: before 2008 NO programmer checked "Stack Overflow" all the time. Before 2000 they didn't even have Google, and before 1995 or so they didn't have much (if anything) in the way of online documentation and similar resources.

That's not ancient history: a 20 year-ish programmer has managed for 10+ years of their career without Stack Overflow.

Windows programmers had the MSDN, or whatever it was called.

MS provided lots of example code and docs.

As many companies did. It came on discs. In the post.

I don't tend to use StackOverflow all that much. Once in a while I'll look up a poorly documented error code on Google and one of the results will be S.O. But, then again, I tend to stick with languages and libraries with adequate documentation.

Honestly, if one is constantly looking everything up on StackOverflow, they're either using a very poorly documented technology or they might want to hit the books a bit and work on proficiency. "Knowing the literature" is becoming more and more underrated.

I think the idea is that after being a developer for 20+ years, one may either develop some intuition about how to use some package even if the documentation is poorly written, or else you have so much experience reading source code that doing so is almost as fast as reading the documentation.

I'm not saying that either of these is correct, but they could be plausible explanations.