When people ask you, what's your excel level? What would you say?

This is a question that comes often when talking to other folks using excel.

How you define your level? If you do Macros, but you don't know more basic stuff, would you rate yourself as Expert because you can do Macros?

Is there a way to standarize how we determinate our levels?
Do you know any good excel self test that would help understand your level? even better, get some certificate?