Being able to read a book and compare it to the movie has helped me to be literate in writing details. I may see a movie and remember a line in the book that was not included. Attention to details has been something I have learned this way.
Shutter Speed, ISO, Aperture ... To be comfortable shooting manual you will need to know what your necessary adjustments are. Though these settings are all numeric, there isnt some insane math equation that you need to do to find out what to dial them i