Hi all, so I'm curious about something.

Any of you who have played cutupuss's custom neighborhoods, specifically Pitstop Valley, you may have seen that certain wants are locked in, already having been rolled. In particular one sim, Ada Smith I believe, has a want for "death of sim" locked in her wants section despite it being a fear. I assume that since it's been done with a fear, it wouldn't be possible in normal gameplay to have a sim organically roll that, and for storytelling purposes I'd love to be able to trigger specific wants in my game. My question is how is this possible? What in the game do you have to mess with to trigger a certain want to appear?