Twelve keys on the ring, but she could never keep track of which one was which.

Every morning, when she opened the shop, she had to try each one in each lock until the door was open, the cabinets were open, and everything was ready for the day.

It shouldn't even have taken twelve keys, she realized one morning, but she wasn't sure which ones might be extra.

She'd carried them for so long that it would be odd not to have them with her.

So twelve keys on the ring, and no desire to keep track of which one was which.