Dunbar number

Dunbar's number is a suggested cognitive limit to the number of people with whom one can maintain stable social relationships— relationships in which an individual knows who each person is and how each person relates to every other person. There is some disagreement to the exact number. Dunbar proposed that humans can comfortably maintain only 150 stable relationships. He put the number into a more social context, the number of people you would not feel embarrassed about joining uninvited for a drink if you happened to bump into them in a bar. Estimates for the number generally lay between 100 and 250.
Perhaps you too could check your 'follwers' to see how many of them you actually remember.