gojonnygogogogo

That's an interesting take on it. I'd always thought it was because: when ATMs were first introduced, people thought of the cash as more important than the card... Nowadays, I'd say the reverse is true for most people: I've occasionally started to walk away from the machine, stuffing my card into my wallet, only to be drawn back by the whirring sound of the cash counter... People are too set in their ways to reverse it now, but perhaps they could give us both cash and card at the same time?

Surely it takes slightly more concentration to walk through a doorway than across a room. You need to avoid bumping into the walls, make sense of an (initially) reduced field of vision, and take-in new surroundings... The idea that people mentally discard information because they've moved into a different room seems far less likely.