The theory behind the technical questions is not whether you can reverse a linked list, but rather:
-Do you know basic computer science concepts
-How are your problem-solving skills
-Can you move beyond "obvious, yet flawed" answers
-Do you exhibit passion (passion to get to the right answer, enjoyment of problem solving, etc)
-Can you present and justify solutions
-Integrity (If you've seen the problem before, tell the interviewer, don't 'fake solve' it!)
-Are you thorough (probing to understand problem, handling error cases, boundary cases, etc)
-Can you communicate/collaborate with the interviewer
Anyway, that's the theory. In reality, many interviewers use whiteboard questions as a crutch to an easy interview loop and don't really understand why they're asking what they're asking.My biggest piece of advice is to remember the technical interview isn't just (or even mostly) about the technical aspect. Communicate constantly, verbalize your thoughts, ask questions, show passion. I've hired plenty of people who have done not-so-well at the technical portion, and I've given a 'no hire' to plenty who have aced the technical portion.