Last night, I listened to a speech given by Steve Jobs at Stanford's graduation ceremony. Here is the link~
http://news-service.stanford.edu/news/2005/june15/jobs-061505.html He came from humble beginnings. In fact, many people and statistics would say that someone like him wouldn't accomplish much, the odds were against him. His biological mother was an unwed college graduate student, the couple that ended up adopting him were blue-collar workers. Anyway, you can see where he is today.
I really believe that if you really want something and are willing to do what it takes to get it, you will succeed. That's basically what I tell my 14 yr. old. He is quite bright and has definite ideas on what he wants to do after high school. Yet, his grades right now (8th grade) don't reflect that. Also, having a strong support system, people that really believe in you and your ability, really makes all the difference.
My husband has many interests/hobbies that he enjoys and wants to pursue further. He really wants to write now, which he has been doing for a while. Sometimes, I just look at him and think,
WOW!. He's always pushing himself, he is a great motivator.
There are no shortcuts, the road to your goal is often bumpy, but you've got to keep going. My parents taught us, through their actions and words, that things worth having took work and perseverance. We went though many difficult times, but we just kept pushing forth.
I'm 40 and returned to college last fall. I see some of the younger students, some have a solid plan and others are there because mom and dad forced them to be there. Anyway, this time around, I'm really doing something that I want to do. I'm really enjoying myself, never thought it would feel this good. I think some people I know expected me to give up quickly, a friend was surprised when I mentioned I had to study for a test. She said, "Oh, you're
still going to school."

I'm done having children, that wonderful stage is now behind me. I'm really excited about this new stage in my life and what's ahead for me.
Bottom line, whatever your goal/choice may be, it should be something that you enjoy and love.
If you keep going forth, despite the obstacles that you encounter along the way, there is at least a chance that you will reach your goal. If you give up because it's too hard or whatever, there is no chance at all of reaching your goal.