I keep the code sheet clipped to my toolbox and work straight off it. But I'm just following it blind, not understanding why any of it matters, so sometimes I miss a detail that would've been obvious if I actually got it. The older guys seem to just know, and I feel like I'm faking my way through the trade.
More people experience this than they realize.
You follow the code sheet without understanding it, so you miss what you can't yet see.
If this sounds familiar, the Library can help you find the bigger picture.