As if buying a day planner and actually using one were two different items. Maybe they are. But in this case, I think the simple point is actually HAVING one.
There are known studies in terms of the cognitive powers of writing things down via old school routes versus our digital age. You can look them up. I think the key point is if you think you’re headed down the wrong path, a day planner does help. Nuff said.
What would be interesting would be if you really wrote down all your plans and not just the ones you felt ok with if you lost the book. Am I off?