Classic gamedev energy right here. You set out to make a simple platformer, but somewhere around year 2 you're implementing your own physics engine because "how hard could it be?" By year 5, you've written a custom renderer that supports volumetric lighting nobody asked for. Year 7? You're reinventing linear algebra because the existing libraries don't align with your "vision." The Carl Sagan quote is perfect: "If you wish to make an apple pie from scratch, you must first invent the universe." Except instead of apple pie, it's a triangle renderer. And instead of the universe, it's your own memory allocator, windowing system, and probably a custom programming language because C++ wasn't giving you enough pain. Meanwhile, someone using Unity just shipped their 47th game. But do they have the satisfaction of knowing exactly how their quaternion interpolation works? Didn't think so.