[mankyd]

That's first sentence:

> Now, you might argue that the number of seconds required to research, acquire, and implement keyhole lubricant would easily outweigh the amount saved through optimal key insertion — and you'd probably be right.

[gorjusborg]

Yep, and good maintenance is its own reward.

The feeling that you are keeping things in working order, and reap the benefit every time you unlock your door, isn't something you can capture in just the time accounting.

That said, it might make for a better article to just mention that it took less than a minute to squeeze graphite into the keyhole, as well as an estimate of how often it needs to be done.