A World of Uncharted Waters
All waters are uncharted territory.
Just because we have a map, it doesn't mean that we've been there before. Someone else's experience may serve as a guide, or plan for us, but is no guarantee of our experience or success.
Just because we recall having been "there" before does not mean that we are somehow immune to the shifting tides and changing sands of time.
In either case, we should not become too emotionally vested in our personal expectations of the coming journey. If for no other reasons than to avoid [self-imposed] setbacks from different experiences or outcomes than expected and to give ourselves the gift of virgin joy and excitement when positives outcomes are the result of that leg of our voyage.
As all human experience is unique to the specific individual, it is perhaps the expectations of our fear and uncertainty that are the only things we have in common with one another.
Water, and the universe, are constantly changing, moving through space and time, so that we are always the first - and only! - being to experience life at this particular place and time...