It doesn't matter whether it's for school/university or for your own general knowledge--how do you teach yourself a certain concept? Do you make notes on the theoretical aspects? Do you have to test it out by being practical with it? Do you read out loud?
When I used to revise for exams, I would take a A4 sheet of paper, several different coloured pens, and then bullet point key facts under different headings. I would then read out what I wrote several times, hide the paper and repeat it again without looking. I would do this for each bullet point, then try to recite them all without looking at the end of it.
I learn best by active listening and reading and writing down notes so lectures with powerpoint slides are ideal for me. I have to really concentrate though. So what's best is recorded lectures, so I'm able to pause and digest information/write down useful notes and continue.Just reading notes and powerpoint slide does not suffice.