I get what you mean I think. However if you’ve been doing C dev for several years and you “don’t remember” what a static variable is and when to use it (or not) is not a great sign. Cumulative signals is what determines hire or no hire, not a single “wrong answer”. Even when a candidate doesn’t know an answer you can get useful signals. If you give them the answer or hints and see how they react or a follow up question after giving them the answer.
You can google many things easily. Understanding the answer and knowing how to apply it to different problems matters a lot more. I still expect some concepts and definitions to be remembered if you’re claiming expertise in a topic.