I think it is great you have a positive outlook. That, IMHO, is the most important thing. Circumstances, career plans often change, but it is nice, important even, to have a longterm goal.
The people who have succeeded in life, (like Olympics gold medalists I've known, movie stars, bands), are positive professional people who wake up each day and give it their best and remain positive. I know a guy who had to give up a major role in a very big film due to a prior commitment because he had integrity. (Think X-Men big). He didn't turn his back on a prior commitment to a smaller project, and you know what? He was offered larger roles later on.
*Positive Outlook
*Professionalism
*Longterm goals
*Work very hard