Having a specific mindset can be useful for those business-minded individuals in being successful. However, success is made, not born which means everyone has the same shot as everyone else.
Don't focus on what's happened, focus on what you are about to make happen.
Find out why that mindset is a key to success.
Let's start with the basics, "don't focus on what's happened", why?
Simple, because it already happened, there's not turning back and there's no changing so focusing on the past is nothing but a complete waste of time.
Instead try using that time to focus on what you are about to make happen, but don't just wait around, do it, work everyday for the future and do that by living in the present not the past.