✔ 最佳答案
Don't listen to the people that say 'never give up', 'giving up is for the weak' or 'winners never quit and quitters never win'. That's terrible advice. A study carried out by Psychology Today (can't remember which issue) revealed that people who stick to maxims like that are usually less successful in comparison to those that know when to give up or when something is a lost cause - as perseverance in a lost cause can degrade your self-esteem and confidence. Not that I am saying that your aspiration is a lost cause however!!
Now in all honesty, no-one on Yahoo Answers can tell you the correct answer to your problem - only you can find the answer to that as only you know the amount of hard work and dedication you are willing to commit to achieve your goal. Furthermore, only you know the practicalities of achieving your goal, for example: whether it is financially feasible, whether your family is happy with you studying overseas or whether you will meet the entrance criteria at all.
What I can answer honestly for you however, is your final question: 'What would you prefer? Practicality or living on rainbows?'
I recently read a lecture by Seth Godin, in which he commented on 'The Dip' (Google it if you want to know more) - and I think the subject of that particular lecture encapsulates your problem precisely. To summarize it for you here however, Godin comments on how the worlds richest and most successful musicians, actors and entrepreneurs, weren't successful because they didn't quit - but they knew 'when to quit something at the right time'. For example, Richard Branson knew he should quit school to pursue his business ventures, and that was a beneficial decision. Godin also says that there are two kinds of success curves: 'the dip' and 'the cul-de-sac'.
When you're in a 'dip' (i'll illustrate like this: ~u~) you keep processing over small bumps and obstructions until you reach the 'dip' - the hardest point of your journey. Here if you quit you will never see the possible/inevitable conclusion, whereas if you continue working hard, you will work your way up and out of the dip and reach success on the other side.
In a 'cul-de-sac' (illustrated as: ~O) the route you are going down will never lead to success, and you will inevitably keep going round and round trying to reach a successful conclusion, but your efforts are fruitless as their is no road out (except the one you came down) meaning you need to backtrack and rethink your options.
Ultimately, the way to be successful and achieve your aspirations is to try and differentiate between 'the dips' and 'the cul-de-sacs' and be aspirational and optimistic - but balance that with a good dose of rationalism. Most importantly, you need to know *when to continue pursuing your goals and when to quit!* It may sound harsh but it's real and true.
You can find out the answer to your first question about Harvard by taking a good step back and surveying your situation and position and weighing up the pros and cons, then making a rational and well-informed decision. Perhaps take into account the views of your parents, teachers etc.
By the way, don't get me wrong. I'm not advocating the idea that you should continue pursuing your goals or that you should quit. I'm completely impartial. And sorry if this seems like a long essay :S however you're at an age where your going to be making big life changing decisions and for that you need good impartial advice.
Good luck!
參考: Me - Life experience
Psychology Today - (Sorry, unknown issue)
Seth Godin - The Dip: The extraordinary benefits of knowing when to quit (and when to stick)
Freakonomics - Steven D. Levitt