Comment by 0xdecade

This applies to more than just CS, but pick a concept and relentlessly ask why it exists until you hit a physical, mathematical, or logical reality that we cannot change/control.

For example, why do web apps use a cache? Because pulling from the main DB is too slow. Why is it slow? Because storing massive amounts of permanent data requires large, dense physical disks that must be located further away from the CPU. Why does that physical distance matter? Because we cannot rewrite the laws of physics -> (Fundamental: data transmission is constrained by the speed of light) -> an electrical signal traveling across a 5cm motherboard will universally take longer to arrive than a signal traveling 1mm from a temporary local cache.

Once you’ve found the fundamental, ascend back up to the surface concept you descended from, and that may solidify the theory a bit. To reinforce it you’ll need to pair it with practice.