Once you accept that we're all imperfect it's the most liberating thing in the world. Then you can go around making mistakes and saying the wrong thing and tripping over on the street and all that and not feel worried.
The easiest way to figure out who the customer is in an online space is to figure out who is paying for the thing. Usually, the people paying are the customers. So on Facebook, the people paying are marketers. That makes them the customers. And it means we are the product being delivered to those customers.