Why do complex building systems still stump me?

You can walk through most buildings and know what you are looking at. Then you hit a system with layers — pipes feeding panels, panels feeding controls, controls feeding something you cannot see — and the confidence drops. That is not a character flaw. That is a knowledge gap, nothing more. Here is the part you have been avoiding: you treat this gap as a feeling to wait out, not a skill to build. You hope experience alone will fill it in. It will not. You close a gap like this the same way you closed every other one in this work — by tracing one system, end to end, until you can explain it to someone else without notes. No one becomes fluent in complex systems by osmosis. You become fluent by choosing one system this week, following it from source to end point, and writing down every place you guessed instead of knew.