British anthropologist and evolutionary psychologist Robin Dunbar came up with a theory that the average person has 150 people who they recognize, name and face. This is referred to as “the social brain theory” or “Dunbar’s numbers”. Dunbar says that we all have a close circle of five people, smaller groups of 15 and 50 that we know and trust on certain levels, and when we go beyond that 150 average social brain, we can remember thousands of people.
This is just a theory, but it applies to every human being. It doesn’t matter if they’re a performer with millions of followers, or some guy sitting on a laptop reading a blog.