Whatever you want to achieve in life it is important to believe in yourself completely.
Even when other people don't think you can do something and judge you harshly. Treat you mean and put you down. No matter what they think or say, you have to keep it in your head that you can do it. It takes a whole heap of courage but if you have the ability to achieve whatever it is your aiming for then don't let anyone/society tell you any different.
This is really a deal breaker when your working towards a goal. If you don't believe you can do it, you will get deterred. And I can't stress this enough, it is likely you CAN its only a matter of how much effort you put in. Your always going to be an underdog, and not many people are going to recognize your effort until you have results.
When I auditioned to be a model for the 1st time. I was quite over weight, inexperienced and everyone else at the auditions ignored me and laughed at me. Some of the people rushing by actually barged into me and literally pushed me aside. No-one talked to me and when I asked someone a question they laughed. Never before have I felt so unwanted and put down. But I just kept telling myself, I have nothing to lose by doing this and I will show these guys.
I auditioned, and I got a maybe. Long story short I eventually did it, I wont go into too much detail (there already is a post on this) and I made it, later I met those same people at the audition and they were friendlier, nicer, respectful and best of all. Jealous. hah!
The other day I saw this fan page pop up on my facebook. Friends had become fans of a lady called Susan Boyle. A awkward, unattractive Scottish 47 year old lady. Shes never been kissed (virgin) and lives alone. And she wants to be a professional singer. She decided to audition for the UK TV Show called 'Britons Got Talent'. On national TV in front of thousands including the notorious Simon from American Idol, she stood up and believed in herself the whole way.
Watch this video, and notice that no matter how much everyone laughed at her, she keep herself smiling and excited. This is seriously one of the most beautiful underdog moments ever.
So you see! Believe in yourself! No matter what others think!