> People tapping me on the shoulder to ask a question while I'm wearing headphones? Before they can speak, I politely say that I'm in the middle of something I need to finish and ask if it's urgent. It's rarely urgent, but people quickly learn that it doesn't pay off to interrupt me.

You can often shorten this to, “can you come back in fifteen minutes?” This is less likely for them to try to pick your brain about whether their problem is urgent or not.

Of course it depends on who is asking. If the head of IT is standing there, and you don’t usually hear from IT, then it could be something bad. If your intern looks like they just set the building on fire, also might be important.