ah yeah, also, don't do pure functional... pass by value is ok for small things but it quickly blows out into a data copy problem and when the data contains pointers as well, then you have knotty puzzles for the GC to deal with as well

there's a reason why the two languages that are most notorious for blowing up your memory and dying due to OOM are C++ and Haskell, one is nasty OOP/template/variant syntax disambiguation, and haskell is constantly copying memory instead of allowing it to be mutated

neither approach are optimal for the hardware, you'll get better at knowing what approach to use with problems as you solve more problems :D don't worry! and do always keep reading those good texts about internals like memory management, that's really important shit, i probably need to do more of this kind of study but i did a lot over the years already