Interviewers aren't going to ask you nonsensical questions about the STL or to use algorithms in contexts that make no sense. The "universe of potential questions" is limited to the reasonable.
Question doesn't make sense? Let them know (gently, of course). Fundamental misunderstanding? Same thing. You are speaking from a position of authority.
I suppose you could try to take that posture in an interview but you are gambling on the interviewer being receptive to that approach.
But that just goes to show it's more stressful and difficult than an interview.
It's not that I'm crap, it's that the tools I'm using are always changing. HTML -> CSS? Sure, I won't look that up. CSS -> SASS? Sure, I probably won't look that up. Ask me to use LESS, I'll be on much looser footing. And, what's coming next? Do I have to have the new ES6 specifications memorized? I don't, though I've used those 100 times already, in the past weeks.
Hell, I still look up git commands.
― Albert Einstein
So. What kind of skills are you looking for? Someone who's memorized a limited set of knowledge and can slap it on a whiteboard on demand, or someone who can get shit done? Not that they're mutually exclusive or even uncorrelated, but why test for a poor proxy of what you want instead of exactly what you want?
That really doesn't make sense, though. They were gauging my experience level by forcing me into a development process I have never used before?
I don't think the best way to test if a person can do X is to take them far, far out of the environment in which they've always done X, and would be doing X if hired by you.
With a client, it's about the software you're developing, with a interviewer, it's about software architecture or coding principles.
In your example about HTML -> CSS I think you missed the point. It wasn't so much to check that you have something memorized, but to check your familiarity with the subject. Everyone sits with a browser while they code - I don't think that's a unique workflow. The thing is, if you've done this HTML -> CSS conversion a hundred times before, you wouldn't need to look it up. They're trying to gauge your experience level and if you've done this stuff hundreds of times before. I bet even a highschool student could find that with Google.
EDIT: I think a more relatable example would be if the interview gave you a simple geometrical problem and you were upset you can't look up the Pythagorean theorem. You're not being tested on your ability to memorize the Pythagorean theorem per se - it's just that everyone is expected to know the Pythagorean theorem b/c it's so fundamental to the sciences. Super simple problem with no google are testing if you have domain familiarity and experience and are a metric of whether you will hit the ground running or not. They're not gauging you problem solving ability, or your ability to memorize crap.