This is a good point. I've always found it a bit daft that previous besties who have drifted apart have to introduce themselves again, even if they are former roommates.
I also have huge family networks across worlds and it's a lot to keep maintaining their relationships so they don't become strangers. My main family has over 20 members over many households across several worlds of all ages and it's difficult to stop them forgetting each other, especially the toddlers and kids with whom it's a bit more tricky to max relationships. So Uncle Nico has to introduce himself to little Rafi when he stops by and so on.
Yeah, I was heartbroken when I had to have a Sim introduce himself to his sister who lives next door. They were childhood besties. Yeah, I got a little distracted with child-rearing and didn't have him go around to see her, but... to have to introduce himself like he'd never met her, when they grew up together? Ouch.
