Not just materials science though. I’m a longtime reader of Derek Lowe’s In the Pipeline blog, and he often emphasizes the trickiness of lab work and lab techniques. But the model we have of science from elementary and high school doesn’t give us room for the random, ephemeral things that come into play in actual experimental work. Our model is methods equal result, every time, even though jiggling your foot a little bit to get the feeling back may have somehow made your small molecule production have less binding affinity or something. And yes, eventually you figure that out and stop jiggling your foot but two years have passed.