“If a man knows not to which port he is sailing, no wind is favorable.” — Seneca
Having goals doesn’t mean that we will achieve them; nor can they act as a source of motivation (at least, not by themselves). The purpose of a goal is not motivation, nor is it a primer to the mystic “law of attraction.”
Its purpose is to generate focus.
To have an end in mind is to see the big picture — as the expression goes, “to see the forest for the trees” — without giving up the ability to zoom in when and where it is needed.