Soul's Journey progresses too quickly.
Once my Sim reached Young Adult I was finally able to start a Bucket List and have some additional goals to work on. Within about two days, he had already completed this first stage without even touching his Bucket List. Just completed a couple of wants and some aspiration goals. At this rate, he'll be done with his Soul's Journey before he's even an adult!
When I created his family, his parents started as adults and they had completed their Soul's Journey within about two in game weeks. Once they reached "Dreams Fulfilled" they can't even do a Bucket List anymore, and everything that was on their list was removed. I wasn't even playing his parents much, just casually taking care of their needs and doing a couple of wants here and there. If I focused on them more, I probably would have completed their Soul's Journey sooner.
The Bucket List is one of my favorite new features, but I was really hoping it would last a Sim's entire life not just two weeks. I literally had to Google to see if there was a cheat to reset the progress so I didn't complete it too quickly and lose my Bucket List. I'm playing on normal lifespan.