Applied data structures and electrical working principles
How are they useful?
Some time ago, a thread on Reddit triggered a long thought process which mostly revolved around the inconvenience of sharing your knowledge on Discord group chats (especially), or servers (less so, but still). Adding something to the discussion is really easy, but even if you don't forget that a certain piece of information is somewhere (way up) there, it'll at least take a while to dig it up. It occurred to me, that it wasn't the case with (oldschool) BulletinBoards, where you could utilize hierarchy to bring order into all the posts.
It's amazing, how Discord can be compared to a list/vector, together with all the complexity every operation entails, and a BulletinBoard is a tree. This simple comparison allowed me to immediately grasp what's so different between Discord and a BulletinBoard, why I've gotten sudden longing for old forums, and how this comparison allows for insanely simple and accurate description of those differences!
But that's just one example; another one would be the overhead of context switching in CPUs - in general I know that when somebody interrupts my work, it takes a while to grasp what's going on, focus on something else, and eventually return to your work. I didn't really pay attention to it, until I've learned how many tricks are bundled with modern CPUs to ease the overhead of context switching. Only then it dawned on me, that my brain has the same issue (minus all the circuitry to mitigate the problem), and it might help to pay attention to my focus and prevent it from being disturbed.
What else is there? With all the fun facts the list might be really long, but it can be a great journey for the reader to discover those.