Wow, this is particularly true when you're not rapid prototyping. An aha moment happens when one is able to reverse think a complete chain of events leading up to a catastrophic failure because you saw a tiny UI/UX bug on the surface.

Paul has written such splendid pieces that should resurface from time to time. This thread has happened [1] to YC community before.

[1] http://news.ycombinator.com/item?id=2988835