Do You Take on the Beliefs of Others?

I learned a powerful principle many years ago....everyone and everything is our teacher.  Meaning, we learn from the good and the bad in every experience and with every person we come in contact with.  This scene from a Rocky movie reveals how often in life, we take on the beliefs of others, and don't take a stand for our own greatness.  
https://www.youtube.com/watch?v=mk82j1jQw_8&x-yt-ts=1422579428&x-yt-cl=85114404