Forget the literal part of the story, that humans are only 5774 years old, or the other quirky aspects to the Genesis story. Rosh Hashanah is a reminder that all humans are equal by having a common ancestor (even if you think its Lucy). We are all one family. And that should set the stage for everything that follows. Basic equality, essential dignity, and infinite value, learning to forgive and take personal responsibility for our actions.
Rosh Hashanah is not about being polyanish to life today, it is not asking us to group hug and sing Kumbaya together it is simply saying this is who we are let us progress and make tomorrow a better world.
Happy Rosh Hashanah