One of the best interview questions I ever had started with the interviewer asking me a fairly routine technical question, to which I gave a standard and accept

One of the best interview questions I ever had started with the interviewer asking me a fairly routine technical question, to which I gave a standard and acceptable answer. He then said, "Okay but what if I took away your ability to do X, Y, and Z - how would that change things?" He did that a few more times in different variations to really see how my answers would change especially as the tools/processes I would be forced to use started to stray from what I knew well.