I also have a Discourse instance for personal use. I use to to track projects I’m working on around the house. I’ve also started using it for some work I am doing with a volunteer org. It’s handy because I can add people to groups that only allows them see the categories specific to that work.
Heck I also used this instance to introduce Discourse to my work colleagues when we were looking to setup community forums 
I use the calendar, checklist, and solved plugins for mine, nothing too fancy.