This app was mentioned in 5 comments, with an average of 2.20 upvotes
I recommend keeping a journal and tracking what you've learned. It's helpful to go back and try to remember the details.
If you have an Android phone, I wrote an app to help with keeping a journal.
https://play.google.com/store/apps/details?id=com.mybjjinfo.android&hl=en
I've been using MyBJJInfo app and its been great, allows for adding session notes and even youtube videos related to that session. It's also free so worth checking out if you are on android.
I'm the developer for MyBJJInfo. If you have an Android phone then I recommend that you try it out. Development is ongoing so I'm still adding new features. You can catalog techniques, videos, YouTube as well, and notes. Give it a try and let me know if you have any problems with it.
https://play.google.com/store/apps/details?id=com.mybjjinfo.android&hl=en
If you are an Android user, I recommend trying MyBJJInfo, download it from the Google Play Store. You can tag YouTube and Videos and organize them the way you like.
https://play.google.com/store/apps/details?id=com.mybjjinfo.android
Along these lines, I suggest trying out an app that I wrote for keeping a training journal. It's called MyBJJInfo. It's only for Android phones right now. Try it out and let me know how it goes for you and if you have any suggestions. Thanks.
https://play.google.com/store/apps/details?id=com.mybjjinfo.android