“In life as in football, you won't go far, unless you know where the goalpost are”

I think that this quote means that in order to go far you have to set goals for yourself. This is saying that if you do not have goals for yourself than you will just stop with your life and not go higher than you are and you will not achieve greatness. When you have your goals than you will try your best to reach them then you will continue to move up and be successful with your life. When you set yourself the goals then will then know what direction to go like with the goal post and then you will go that direction to achieve them all little by little. If there were no post on the field than the players won't know where to run and also they will not be able to win anything or any points.