Sadly, many interviewers will be fine with someone who simply memorized without actually understanding much, and not fine with someone needing to think and slow

Sadly, many interviewers will be fine with someone who simply memorized without actually understanding much, and not fine with someone needing to think and slowly coming to a solution, being able to explain it, because oh that did take more time than the interviewer had allotted for the task. Sadly, many interviewers and the adjacent HR departments are utterly failing in the communications part too.