I've realised that setting high goals can turn into an obsesssion. You find yourself fixated on the goal you've set, more than on putting in the work to get there.
By thinking of the ultimate result, you may accidentally craft a sense of fear of failure. For example, if you know you need to get a certain grade in a class, then you might frame your mindset into a fearful one.
Once you've become convinced of the horribleness of failure, you fixate on being perfect.
That's where you begin to procastinate. You procastinate in fear of failing your goals. So you never start, because everything has to be perfect.
This is like a self-constructed trainwreck.
Better to work on doing your best. You will never know if you are perfect. But you will know if you've done your reasonable best.
Yes, it's good to know your goals. It gives you motivation, it sets a direction. But afterwards, focus only on things you can control.
This would be the time and effort you have available. The hard work and time management that is neccessary.
This mindset is freeing and helpful. It lets you focus on the now, rather than the fearful future.