How does one say goodbye?

How does one know, that goodbye is what it is?
That this moving on, is for better, that is…

How does one fly?
Soaring is a powerful thing,
But how does one soar on weakened wings?

The road lies before me again,
Its the same that followed me too..
The same road, the same mind,
What goes forward, who stays behind?

Tell me… how does one say goodbye?