What is the central idea of lewis’s speech? why might he have chosen to express this idea at a princeton graduation ceremony?

Michael Lewis is an author who himself is a Princeton graduate. In his 2012 baccalaureate commencement speech Lewis talks about success. He claims that successful people are actually lucky even though they are trying to hide that factor from people. Their stories just presented in a way that even world ignores that they were lucky. Indeed, there is a debt has to be paid to unlucky people that lucky people are born from their experience.  

ladies and gentlemen, this message that you will hear is to my family:

dear family, you so much for giving me a possibility to live and i am happy that you took care of me and always telling me that i can do everything that i have in mind, you trusted me and still do it, i don't think i need to ask you for more, i love you.

you so much for listening.

hope this you.

every person should make it a priority to serve at least two hours per week.

it's an extremely important civic responsibility that is invaluable to citizens most in need is the correct one