The problem is that since I'm rarely the first person into the office (no laughing at the back, please!) or the last person to leave, the time lag between me being told the new codes and actually having to use them is pretty long. Short of writing them on a piece of paper in my wallet, how to remember them?
The trick I'm trying: every time I get to work in the morning or leave in the evening, I try to remember the code before walking through the door whether I need it or not. Hopefully by the time I actually have to use it, it'll be stuck firmly in my head.