No, not those buttons. The other buttons. The hot ones.
Okay, not those hot buttons, either.
What I'm talking about are the little things that you find utterly maddening, and which anger you beyond any kind of rational level compared to whatever sets them off. For instance, if I've gone to extra effort over something for someone, and that person inconveniences me, I go from calm to nuclear between one heartbeat and the next. Another one that gives me issues is when I'm expected to follow the lead of someone who - in my highly expert and infallible opinion, of course - couldn't organize a piss-up in a brewery. I'm sure you have a few of your own little glitches like that, probably including some you don't want to admit to.
Characters need hot buttons like that, too. And stories need to push them - because that's when your lead, or your villain, or whatever, is most likely to do something irrational which triggers off the cascade that makes things worse. It helps, of course, to establish the hot buttons early, so that when they get used later readers don't wonder where the heck that came from.
I'm going to use - carrying on the theme from Sarah's post - Darkship Thieves as an example. One of Thena's hot buttons is being physically restrained, so much so that she's prepared to commit murder and mayhem, not necessarily in that order, on the person who dares tie her up. We see this in the first few chapters of the book, so it doesn't seem at all out of place when Thena goes nuclear later in the book. Of course, she's got a few other hot buttons as well, and Kit isn't exactly the most level-headed person ever, either.
Who and what else uses character hot buttons well?
p.s. Apologies for being kind of scarce and not entirely with it. It's now a week since the layoffs, and work is totally batshit insane busy. I'm not sure when things will settle down, since the backlog was impressive before this happened. Now it's more like a cliff about to land. Such is life.