I learned that same lessons as you did. When I started using Blender I wasn’t mindful of performance, I didn’t know things took up memory, I just slapped a subdiv at level 4 to everything. After a few snag like those and errors and scenes that could barely move or load, I started to change how I approached building a scene from the very top. Always mindful from the very beginning of performance and not overloading things. The amount of headaches I must’ve avoided I wont even ever know.
