About 6 years ago I was having breakfast with my, then, 6 and 4 year old sons. We were all quietly eating when the younger asked, "Dad. Why do people have two holes in their nose?" Good question, I thought, and stumbled while I tried to think of the answer. No need to worry, my older son got in first, "Don't be silly! It's so they can breathe while they're picking their nose." Better than any explanation I could have dreamed up.
(From the "Rest" of RHF)