You're right. I've recently answered a thread here about being a restarter (someone that just starts over and over and can't keep a game going). That made me think a lot. I was always a generational/legacy player. In sims 3 i went easily on one save to the 6th, 7th generation, although i've never reached the goal of 10 generations. But now, in sims 4, i can't. I get to the 2nd generation and im fed. I think this is because sims are just all the same. I always randomize traits (even before the official randomizer existed) and they don't change. I need to be constantly imposing rules to each generation. But its just not the same. In sims 3 sim's lifes unfolded because they had their own dreams and traits that actually influenced their behaviour. They felt romantically atracted to some sims in detriment of others.. it was more umpredictable, more interesting.
