Sims who are “Not In World” exist to give your Sims others to talk to (referred to as “Townies”). Note there is a third “world” of sorts called “Not In World,” referring to the Sims who exist but outside the confines of neighborhoods.
To illustrate, here's a picture of the World ( Oasis Springs) in which Pyro and Pete Falkon live.Īnd here is the neighborhood in which the Falkons live, with their lot highlighted.