One thing you can rely on is that there will always be uncertainty.
Nothing we do can change the past, but everything we do changes the future.
Not only don't I know what tomorrow will bring, I'm still not entirely certain what yesterday brought?
My cat knows the meaning of life, but has no interest in sharing the secret.
Sometimes I need what only you can provide: your absence.
The fact that many things have no explanation ought to prevent them from happening; but it doesn't.