I kind of get it, but just like Ikea instructions, you start second guessing yourself, then you realize, its BACKWARDS after you flip back 5 pages in when something doesn't fit.
Are you on about the ones where the bottom is carboard that could go either way? LOL I hate building those.
Ikea instructions are like an Easy to Medium level test in reverse engineering skills, with occasional EXPERT TIER SUPREME level skills needed because of subtleties.