It is important to have big goals and dreams to reach for. When something is out of reach it keeps us striving and working towards the goal. You feel motivated and inspired because you are reaching for something worthwhile.
And once you reach your goal or destination enjoy it, but do not grow complacent. Find another goal and dream to reach for.
The more detailed and defined your goal is, the better because it is impossible to reach a target that does not exist.
So create a dream and keep reaching until you make it your reality!