App that tracks your "learnings"

I think it was Naval in a podcast who said that he's been writing down his learnings or takeaways for the day.<br><br>I think it would be a great app and in perfect timing of the post-2020 digital craze if there was an app to record your learnings and even categorize them. Maybe the app tracks it on a calendar and sees what you learned on a particular date in the past and lets you compare if it's still relevant to your life or not.