Totally missed the humor in this when last I tried to read it. Probably so did most... (all?) Recall once reading it in an English class. No doubt the teacher had no clue. High school was a horrific zoo.
You have the horror of waking up as a bug. But then you have him thinking about still getting to work on time. I suppose I must have dismissed the work talk as something to give a plot and not make it too short, etc. IOW useless stuff that is often thrown in bad stories. Stuff that disobeys that idea that everything should be "essential" to the story.
Reading it now I see that the idea was to show a life so bad that waking up as a bug is almost not quite that big of deal considering what's come before. He's already been put through such crap that this is just some more crap to deal with, still better not be late for work! That's funny, in a way...
From reading Kundera's nonfiction it seems that perhaps understanding the humor in Kafka is the key to getting.... the key to really appreciating his stories. In the Trial for example at the end K is executed. And he almost wants to stab himself as he's convinced himself he must be guilty of something.
Truly an important (and funny) idea. The openminded, good person is (of course) in the minority and persecuted. But because he's so damm openminded (and of course good as a result) and there's so many thinking badly of him, (which, of course there's so many, it has always been a small minority that is openminded to any meaningful extent and they're usually not liked by the rest) he can't help but really wonder if he's doing something wrong. And being a critical person it's easy enough to realize we're all far from perfect.
And by being a good person stuck in such a world he ends up persecuting himself. Which is funny. And I've added a whole bunch that probably wasn't in the original Kafka story. But if done really really well, would be there... I think.