Tell me about yourself

I find myself staring at a piece of paper, it is a set of mock interview questions and the first one is "Tell me about yourself". This is a standard question that I have answered hundreds of times in my life and yet here I am at 39, staring at it with a blank mind. There are so many ways I can answer this question and yet I feel like none would be sufficient enough to tell about myself to someone new. How do I start to answer and where do I being? Do I begin with my origins, where I was born, where I was brought up and who are my parents? That seems so factual and basic, like a census of a country, or like a fact list about my existence. I can walk them through my professional career and here too it is not a one word answer, the various teams and types of work would be a long list. Sometimes the variety of things I have worked on or tried out just makes them seem all over the place to consolidate to anything substantial, at least in my head. Why now is this question seeming so heavy and intellectual and philosophical when it is the most basic question there is out there?