I think the game should implement a version of the Sims 3 Scrapbook Memory system, rather than the Sims 2 version. While in theory I prefer the Sims 2 Memories better, I find that The Sims 3 version would not only be better suited for the Sims 4, and less intensive on the games engine. You could have the game have certain emotional and relationship triggers based on the memory— with Sims reminiscing about their first kiss together, remembering that their grandparent passed in the kitchen, etc. and have moodlets accordingly, or randomly appear.
I originally had an idea that this memory system connected to a revamped social media patch that (I believe) the Sims 4 desperately needs. Where Sims could share their memories online to “SimBook,” but it can be brought about in a number of ways really. All they need is to make sure it doesn’t cause bugs, nor completely crash the game.
