"Keep away from people who belittle your ambitions. Small people always do that, but the really great make you feel that you too, can become great."
--Mark Twain

Case in point:  Tell some loser you want to own huge corporation some day, and they'll not only laugh at you, but tell you all the reasons why it "can't be done".  Tell an owner of a huge corporation the same thing, and he'll not only commend you, but ask you if you need any help along the way.  

WATCH CAREFULLY WHO YOU HANG OUT WITH.  
Possibility thinkers, or losers?   

You are the books you read, 
and the people you surround yourself with.  
Remember that.