Aspirations and traits lead my sims lives, and things fall more naturally with this. Careers and relationships according, culinary sims work at the pub or kitchen, mean sims make enemies from minor inconveniences E.T.C. Pleasant Sims system for randomizing favorite colors, gender preferences, and hobbies for a more natural game. But mostly, my sims just do little things as they go along, play in the leaves, beach comb, brush their teeth, festivals.
EDIT: Probably meant natural, if it were absolutely real, sims would not have so much achievements... Do still follow most real things, and a lot of what happens, is this way in reality. Maybe I meant fictional context, because sims get to be famous chefs if they want!