I recently went to PC maintenance and repair courses. When I was recorded, I was told to prepare 10 DVDs - they would throw me books with educational films.
Waiting for the first DVD. After I was given it, I strongly believed that I could not have enough of ten... They gave me books in the Word format, and every word page was scanned... In the end, the 400-page book had almost a gigabyte (in djvu it weighs 6 MB).
My confidence in these courses fell slightly.