It happens. People don't always understand what's involved in the situation, even if you try to explain it to them ahead of time.

[Derek had had slightly more choice than her; either forget how he found out about vampires and go about his life, ignoring the fact that they were out there, or get involved because not only did he know, but he had the capability to take them on when others didn't.

He didn't have to choose to take the job; he just couldn't stand by knowing that other people were suffering from something he could fight against.

Better it was him than someone else.]