Most people are too focused on the what and the how of what their goals are and never give much thought, if any, to the why.
Having a why makes sure your goals become real. Your why needs to be big enough so that it gives you motivation and keeps you hungry for your goal.
For example, my why for starting my own business was so that I could work from home and spend more time with my daughter. But you can also dig deeper than that by asking why do I want to spend more time with my daughter? Your first why might only just scratch the surface so keeping asking why till you get to the reason that makes your heart sing.