I needed it, which is why i was not able to continue... trying to keep up working 15-20 hours a week, 15 contact hours, being a mum, wife, cook, cleaner etc...
and being pregnant and exhausted i just couldn't fit it all in.
I think it depends on how long it takes you to read, understand, and then contextualise what you are doing. For me i have to do it several times until i am satisifed i have a clear understanding. For others they pick it up real quick. Biology (A&P) was consuming me and it was probably 20hours a week instead of just 10!