Most of the people want to become successful over the night, usually they want to do it very fast. Maybe in a short term they can do it, but on a long term certainly not. But I personally think, that sometimes its more important to do the small steps and even to do some mistakes while you are trying to achieve the goal. That is how you learn, you get more experienced and in the end, you really appreciate all the things which you had to do, since the beginning to the end, to achieve the final goal. So I totally agree with the statement.
I personally think, that for every person, being successful means something different. For someone being successful means to be healthy, for someone else means to be extremely rich, again for someone third just to have a family and a warm place to stay. Every goal which we set up for ourselves needs to have a clear vision, how we would like to achieve it. In my case, I'm always the most satisfied when I achieve the goal for which I worked hard. For example, I train football every single day in the week. And I know that I cannot become the best football player in the world over the night. It takes months, even years to achieve that. And I'm still motivated to do it, no matter how long it will take. And my success is when I score for my team. And I'm not doing all this things because I want to be rich, famous or something like this, I just do it because I like sports, I have many friends in my team and I want to live healthy. And that is a key to success. You need to have a passion for it.
To conclude, in my opinion everyone has a potential to be successful. But only those who have desire, the will, the motivation, will make it through the journey to a destination, the final goal.