[soks86]

I've explained bugs and developed exploits just from noticing odd behavior in video games.

I know how a team is organized, I knew the multiplayer feature was tacked on (probably by interns), I know about network code edge cases, bada-bing bada-boom I can trigger a bug and understand why it happens without ever seeing their code.

Or sitting in a theater and just noticing the lighting setup and transitions rather than the performance itself.