It's rude to be late for class.
Penelope is in college and her chemistry class starts in five minutes.
Penelope wants to get some extra sleep.
Penelope runs to chemistry class on time and goes back to sleep after class is over.
Penelope sleeps thirty more minutes and stumbles into chemistry class late.
The chemistry instructor is happy and so are all the students.
The chemistry instructor is angry and some students lose their train of thought.