In my head it has always been something along the lines of "to affix materia to an armor you need to understand how it is made". I might want to power up my computer, speed up my car, improve my lamp or dishwasher, but if i have no idea how these are actually put together or how they're actually made then i can't improve upon it. I know how electricity works in theory, but could i build or improve a turbine to produce it? nope. I know how a motherboard functions, but could i build one or improve it? again nope.