The question "What do you do?" has basically become synonymous with "Who are you?" There's a reason it almost always follows "What's your name?" in polite conversation: It's helpful. It's get-to-know-you shorthand. The one-word answer to "what do you do?" lets people categorize us and gives them a snapshot of what we do or who we are.
But there's also a dark underbelly to introducing ourselves with this kind of shorthand: When labels go wrong, they can lead to stereotypes. Perception becomes more about the experiences accumulated by the people you're talking to than anything that they may or may not know about you, personally.
