Egocentricity is the name for that way of being: thinking only, or almost only, about yourself, and not really taking in other people's needs or feelings. It is the noun that sits next to the adjective egocentric. You will meet it in psychology and in fairly formal writing more than in casual talk. A child psychologist might speak of a toddler's egocentricity as a normal stage; a critic might complain about a film star's egocentricity as a fault. In everyday English, people are more likely to say selfishness, though that word often blames the person for choosing themselves on purpose.