I love the bad-assitude of knowing a system so well you can simulate it in your head, feed inputs to a third-party who actually has eyes/hands on the real thing, and have the state in your mind and reality match. I think of it a little bit like using a human as a convoluted (and sometimes unreliable) expect script.
I was a telephone customer support for WordPerfect back in the early 90s. Walking through our cubicles, you'd see most of us leaned back in our chair with our eyes closed talking people through WordPerfect's menu system to fix their problems. At some point, you just don't need to interact with the software to know what's on the customer's screen.
As I had sweated night and day on these systems for 3 months, unsurprisingly I knew exactly everything about them in and out :)