Mark Zuckerberg quotes and aphorisms about people Mark Zuckerberg Mark Zuckerberg ,, Really, who you are is defined by the people who you know - not even the people that you know, but ... Mark Zuckerberg Mark Zuckerberg Mark Zuckerberg Mark Zuckerberg Mark Zuckerberg Mark Zuckerberg Mark Zuckerberg Mark Zuckerberg