How do you actually play multiple Sims and multiple households in this game?

I play multiple households and multiple sims. I travel with the sims I want and leave the rest home. It's not a problem for me and I prefer it this way compared to TS2 where it was like time didn't pass at all. I understand TS4 way doing this might feel weird at first, but once you get used to it there's nothing stopping you from playing multiple sims/households :)