Maybe the solution could be to keep them in both versions, digital one for reference and a physical one for learning and retention.
For the digital one, one can just copy and paste, use abbreviations, templates etc. so it doesn't take a lot of time.
Obviously the physical notes are only necessary in learning new and hard material. For example one might keep a notebook for C programming, Assembly, Basic Algorithms, Discrete Math etc.
I must admit that I've never tried to print my digital notes, which I keep in org-mode and export to pdf using tex. I guess that could also help for studying. You could take notes with hand, highlight things, put stickers on it etc.
I am planning to purchase a laser printer with refillable toners to print books, papers and my notes. I don't know why but having a physical copy of things help me learn them much easier. It could be that it is the only way I learned in school.
On a sidenote, during highschool I could only write essays with real pen and paper. But now I'm used to firing emacs and writing prose. Maybe I could also train myself to read textbooks on a computer efficiently.