education
you can get a passing grade without ever really encountering the material you are supposed to study, because something else can produce a plausible-sounding answer for you in two seconds. even before any of that, i do not think the system was measuring what it claims to measure. grades reward format and test taking skill more than they reward actual understanding or ability. a lot of genuinely capable people fail at it, and a lot of people who are good at the system get credentialed without ever being tested on whether they can actually do anything with what they supposedly learned.
how i actually try to learn something
the stuff i actually remember is the stuff i went down a rabbit hole for at 1 AM because i wanted to know. the moment right before you understand something is uncomfortable, and it is also where almost all the learning happens. skipping straight to the answer skips that part entirely. i learned more about networking from breaking my own home server than i did from any course. read the actual documentation and source code, not just someone's summary of a summary. running workshops and similar for LiTHe Hax taught me more than being in the audience ever did. you find out what you actually understand the moment you have to explain it out loud. asking "why does this work" or "what am i missing" is completely different than writing the answer. find a CTF team or a discord full of people nerding out about the same weird thing. learning alone is possible, learning with people who are excited about it is better.