I've felt this, and I agree. It really pays of to do some work on technical discovery, make all the mistakes, see where all the design issues will be, validate

I've felt this, and I agree. It really pays of to do some work on technical discovery, make all the mistakes, see where all the design issues will be, validate as much as possible, and then start again. And the best way to really scope out requirements and get to know the "unknowns" is really to get your hands dirty. Especially when in comes to business logic and domain modelling, some bad decisions at the begining can cost a LOT, to undo in an iterative matter. (To clarify I'm talking about the timeline the author proposes of "a couple of days" build the throw away prototype)