Ambitions

In my opinion, it is very important to have ambitions for our future. It is necessary to have goals to reach, because this is what gives you the strong will to give your best, but most of all, to live. No matter what kind of ambitions it is, whether small ones, or even the ones which seem irrealistic at the first sight, you have to believe in yourself, in your dreams, and to give yourself the means to succeed.
We don't have to neglect the role of the parents in the success of their children, because they have a significant influence in their life, and they are able to encourage them, and to improve their self-confidence. They always should help them to fulfill their dreams, even if they seem crazy or kind of stupid, and wipe away their tears in case of failure. A failure can help you, to the extent that what doesn't kill can actually make you stronger and give you some experience. 
Don't put limits on yourself, because having realistic goals can sometimes be boring. Everybody is secretly a dreamer, and we must assume this part of us. 
Nevertheless, ambitions can be very harmful. Firstly, they sometimes push people to act in a wrong way in order to obtain what they want, even if it hurts the people around them. Secondly, some people are ready to deny who they really are to succeed, their personality, but also their past, as we seen it with the extract of the movie Pygmalion. You actually have to adapt your ambitions with the person you are, because it isn't necessary to change yourself, unless you deeply desire to become a new person. 
My personal ambitions are to achieve my higher learning brilliantly, and to obtain a job which could allow me to change the world, to save it.

Don't let anyone discourage you, because everything is possible (almost).