You Can Track Literally Everything
Bullet journals are well-known for being great tools in the workplace or for schoolwork because of how well they can help you stay organized. This is totally true, but it can be used for so much more than that. Personally, in addition to work, I also use my bullet journal to track things like my mood and eating habits. Putting the ways I'm feeling or eating every day down on paper helps me understand my own habits and patterns, and how I can change or improve them as I see fit.