It's not just ROI that drives us. There's an implicit capitalist motivation behind to-do lists and checklists - check it off, accomplish a task, and feel like you've earned a reward.
Most of us don't put day-dreaming, listening to music (not to inspire productivity as soothing, motivating or inspiring background to our ROI driven tasks, but just to listen to music), or doodling on our to-do lists... all habits of highly productive people, but we don't know if these things are worth it.
Same goes for learning things that don't have a pay-off... or a pay-off we can measure.
So how should we measure things we can't find an ROI for today?
Check-in tomorrow for an answer.