Another embarrassing discovery is that the thing in question isn’t working because you didn’t turn it on. This rule could come first, as in some sense it’s more basic than Rule #1, but for the simple AC-powered appliance, you have to plug it in before you can turn it on, so I list it second.
Again, there are lots more useful ways to think about whether you’ve turned something on. For instance:
You might have checked one power switch. Are there more or different parts that also need to be turned on? The monitor, the printer, the router, the speakers, the amplifier, the power strip, the ground fault interrupt, the circuit breaker? Are the batteries still good?
Was software told to go, execute, connect, activate, initiate? Did you single-click something that wanted to be double-clicked? Did I actually press Send on the e-mail? Did I post the crontab and start the cron daemon? Is the server running? Did you set the right bit - and was it normal or inverted logic? You turned on the switch, but was it wired to the rest of the circuit? Were error codes checked, so you’d be notified if something wasn’t on?
Did everybody know that today was the day? Was it part of the job description? Did anybody call to place the order? Did you assume someone was on track, available, or in the schedule without checking?
You want it, but did you say so?