Your demo works because you know where not to click

Everything I've built fast worked perfectly for me and fell over for the third person who touched it. Not because the code was worse than I thought. Because I'd quietly learned the path through it. I know which field to fill first, which button not to press until the save finishes, which page to reload when it looks stuck. None of that is written down and none of it is in the product.

The test I run now is to hand it over and say nothing. No walkthrough, no "just click here first". Watch where they stop.

We had 111 options on our first screen. My demo of it was fine, because I never scrolled, I went straight to the one I always use. Real people scrolled, decided, and left without making a single thing. No amount of me showing it off would have surfaced that, because the demo path and the cold path were different paths and only one of them was in my head.

The part that bothers me is that this gets worse the faster you ship. Speed means you pile up workarounds you never write down, so your own fluency with your product becomes the thing hiding its problems from you.

What's the thing in yours that only works because you know how to hold it?