I had questions in my repertoire that came from specific situations I had at work. Things like "Your application fails with a message 'There is no space left on the device' but when you check the filesystem you find there is a lot of space available. What could have caused the problem." Or a static initialiser block in Java that was executed multiple times when the application started causing a problem.

I found I was just comparing somebody elses experience to my own which is wrong. I should be trying to figure out if the person is able to do the job.

So I stopped asking those questions and instead I am selecting topics that every developer should know and constructing specific situations where the person with the knowledge of a given topic should immediately recognise what is happening.