the detriment of education

i'm painting the monkeyface on the big mushroom. i just finished the eyes. they're done, i'm not touching them any more, damnit. anyway, i was sitting there pondering their doneness when i realized i should have painted the mushroom cap and the monkeyface at the same time, using the colors on the cap on the monkey's eyelids and shit where the monkeyskin shows through the monkeyfur.
seems pretty obvious, right? not when you're more worried about exactly what shade of weird purplish-gray that is above the black, and the fact that that purplish-gray is monkeyskin showing through monkeyfur and that black is an eyeball is the last thing on your mind.
after all, why worry about how you could tweak your stupid collage into a really badass, cohesive piece of work when the real objective is to mix colors really accurately?