Spent.

While attemtpting to exit my local Burger King just now, carrying a freshly bought and about to be eaten Crispy Chicken™ burger, I stood in front of the doors for a good four seconds, wondering why the hell the doors wouldn't open, before I realised that doors in question were, in fact, push doors as opposed to sliding doors.

Four seconds, while negligible in the context of, say, a human life, is a surprisingly long time when spent waiting for a door to open.

Working 12 hour days three times a week might not be such a good idea after all.