I don't expect it to be better, but different, hopefully good in its own, Sims 4 way.
Sims 2 memories could be passed through Sims via gossip and have consequential results. I remember I was playing a family of three; father, mother and reen daughter, who had a positive dynamic, well adjusted family. I switched households to play some romance Sims, went to the goth club to hit on whoever was there. The father showed up outside so I took my Sim out there to flirt brazenly, out on the street, with other Sims passing by. They had a short flirtation, I think had one kiss and then he left.
Eventually I went back to playing the family, and the teen had a friend over who had been by the club that night. Suddenly my teen's relationship plummeted towards her dad and she went to her bedroom and cried. I was confused for a time, wondering what happened to their relationship, until I saw there was something about his "betrayal" in her memories. I'd had no idea that this could happen, that her friend could pass that information onto her. Changed their relationship forever, took a long time to get her to stop hating him, but she never told her mother and he never did it again. That was some amazing gameplay.
So I definitely don't expect that level of memories to exist in Sims 4, I think it's something that would have to be programmed from the core game in the beginning. But in Sims 4's version, I think it will be able to change a Sim's emotions when they think of their Milestones, so in its own way it will have a unique effect on Sims that will hopefully feel different for each Sim depending on their personal experiences.
I do hope they will include a lot of different types of milestones, unique to traits and special circumstances whether good or bad, so that they don't start to feel like they are the same for every Sim. We really need more distinguishing characteristics.
