There are a few things Charlie doesn't think too hard about. Where did he put his keys? Did he eat lunch today? Does the houseplant by his desk need to be watered, fed, repotted or put out of its misery by throwing it off the roof?
Not thinking about these things allows him to focus what he's good at.
What Charlie absolutely does not think about are the odds of getting injured on the job for a FBI field agent in L.A. Especially now that Colby is a perfectly reasonable 22 (22 and ½, 23) minutes late and hasn't called.