Why do we ask questions?
Because we do not know the answers...
But... there are some instances when people still ask questions, even though they already know... and they do this for two reasons:
(1) To confirm if the person asked shares the same opinion as to the validity/correctness of the "expected answer"
(2) To validate the person's knowledge of things that he/she is supposed to know
For the most part, both of these are done mostly by people in the academe. (#1 is practiced during research, #2 is, in some sense, for "tests"/"quizzes"/"examinations"/"assessments".)
Such and such are the scenarios, for questions which we could (conceivably) ask about the world (from the "microscopically minuscule" to the "astronomically humongous").
However, there are some questions that some people have already dared to ask, yet for which we still do not have any satisfactory answers, not even close to partial - to wit:
From the Problem of Evil: If God is a loving, caring and omnipotent Father, then why do bad things still happen to good people?
From a Millenium Math Problem: The Riemann Hypothesis