Do you know how I get to the post office
do you know why he left so soon?
I think it is metaphor, because it wasn't really exaggerating
A question is a great way to use as the hook of an essay.
Starting with a question about is a great way for the reader to want to learn more about your topic. Good questions to hook a reader is; "Could it be ......?", "Why is it .......", "Did you ever know .......", and "Have you ever hear of ......"