Success is required to mentally focused. When we focus to anything, we are always in present moment.
And when we are not focusing, we are either in the past or in the future. Every person who is not in present moment , he/she is in past or future and cannot make intelligent decision. His/her decision will always be bias.
Tips to boost focus
It is difficult to stay focused when someone worrying about the future, overlooked of the present moment, or ruminating about the past.