I started working regularly at another office. After a few visits, I figured out where the microwaves were and decided to bring my usual packed lunch.
The microwaves here were different to those back in my usual office. There was a time when it was obvious how to work a microwave — turn a dial for heat level, turn another dial for time.
New microwaves, though, bristle with buttons and glowing blue displays. With the ones at my usual office, you have to first select the power wattage (I always go for 900) and turn a numberless dial for time.
The ones at this new office were more complicated. They was some kind of microwave/oven combo.
I scratched my head for about 15 seconds, then pushed the blank button in the bottom right corner. The button had once had text on it, but it looked like the text had been rubbed away with use. I figured that it must have been the most popular button so was probably going to do something useful.
Sure enough, 30 seconds of heat appeared on the display and the microwave started whirring. After that, it was simple matter to add another two lots of 30 seconds.