At first I was like "Whatevs" when people talked about it. But my first save got to a third generation and they added the family tree thing, a couple of days later the Sim I started that family with had disappeared (Well, he was dead, but his ghost was around) and suddenly his paintings only said "Made by: " and a blank space, not even showing his name anymore.
Lol! Actually, now that I remember, last night I was playing my current household and a very attractive male Sim walked by my lot and I was like "WHO is that?! He's cute, go talk to him" and invited him to a nightclub just to get one of my girl Sims pregnant and ask him to move in with us. Yes, I did that because I'm scared the game would erase that Sim.