I've been fascinated in Ebbinghaus ever since the OU introduced me to his work. I've come to believe that this is a generalisation. Like all populations there are outliers: in this case, those who are better able to hold onto information and those who are not. I am on the 'do not' end of the scale. A lecture or class followed by review and homework and testing, then further prompts and exams worked for me. Anything less and I lose it. I don't concentrate enough in the class or lecture anyway, even note taking becomes mechanical.
This work offers explanations and methods.
REad the short paper by 'The Forgetting Curve' by Dr John Whitman