Being a lucky person in life depends on a variety of variable factors depending on the personal nature and surrounding circumstances. Few people cannot perform well in school, but ultimately they are even more successful in practical life. There are many factors behind this including core competency and availability of different opportunities during student life; however, I believe that significant requirement to become successful in life is consistent hard working.
One of the primary reason for this conflict is an incompatibility between natural talent and practical life because sometimes people have the passion for something else but doing something different. For instance, many athletes were not interested in studies at all, but when they found their compatible field, they made history in that. Furthermore, sometimes students find some lucky opportunities, and they take the risk to jump into those. So, it always depends on the selection of right subject to do which is in line with personal passion and sometimes some fortunate opportunities change people lives.
In addition to this, I believe that most valuable thing to become successful in life is consistent hard working. The consistency is even more important than hard work because it makes sure the fruitful result of a project, especially long term. This is the fact that most of the billionaires in the world continued their same business lines instead of many ups and downs in their life. So, consistency is that element of whole life which will always assure the good results of any activity.
To sum up, life success does not depend on single reason like academics mainly due to conflicting competencies. There are many other factors, which are even more important than school, like doing hard work on regular basis.