How do you keep things fun/interesting? Considering playing as child up instead of starting at YA.

I have one save with a sim who's entire goals revolve around completing aspirations so he goes to Batuu, he has uncovered all the secret worlds, completely leveled his spell casting, will do the Strangerville storyline (although I did that on another sim). Then I have my main save with my 9 families so I am doing all the careers, all the college degrees, etc. I started it all with one sim, a rags to riches sim. So start with one, give her parents and maybe a sibling. Grow your story from there!