Careers

What truly defines a career, especially in the area of ministry. I mean, with a doctor, they know their career will be in medicine, in a specific area, they won't go from foot doctor to neuro surgeon overnight, but a youth pastor could become a senior pastor. I was recently asked how serious I am about youth ministry. how should I answer that, if that means its all i want to do in life- who knows. If it means I care deeply about it and want to be involved in it for at least the next decade or so, then probably.
Anyway- thats just what I have been thinking about. HOw do you define a career this early in life? I mean, say I graduate with a degree in Christian Ministries- am I then going to have that as a career immidiately, or must I accomplish that. They say you are "pursuing a career in..." when you're in college. That is dumb, we are "pursuing" paper saying we can do a certain career, sometimes.