"We are twins," said G-d -- in a Midrash, I think. "I am not older than you. You are not older than me." Meaning: G-d and the Jewish people entered the world at the same time.
One of the twins is hiding.
It is curious that G-dliness is obscured in the world, that we mistake people for what they are not. This is an unnatural state for the world to be in.
Tolkien once identified the conflict in Lord of the Rings as between nature and machinery; that will do for an analogy.
Through most of the year, even the Three Weeks -- which so neatly align with vacation season -- it is hard to shake the impression that life, while not perfect, is about as good as it can be.
And then comes Tisha b'Av, which was yesterday, reminding us that there is infinitely more to it.
Tisha b'Av is the day when everyone sits on the floor and mourns that the world is still in this unnatural state, not as it should be. A kumzitz of the shipwrecked.
Tisha b'Av leads up to Elul, when we take steps to see what we can do about it.