I must again agree with my Organized brother. Very rare is the man that loves his job. That my friend is worth far more than you can imagine at your age. Yes college is great. But trade work should not be dumbed down to a last resort for those that can't cut it in school.
Our trade desperately needs young men (& women) that love the work they do. I think it is sad that a young person expressing this much interest in being a career plumber is being discouraged by plumbers.
What's wrong with sticking with a career you love, has a respectable wage, and is likely to never be eliminated? Pursuing the pot of gold in the white collar world is a tough row to hoe. There are a lot of degreed professionals working the night shift at 7-11. On the other hand...a bright, energetic, sober, clean, professional, well spoken, hard working young man will never be out of work with a plumbing license in his pocket.
Stay the course Kid. We may give you grief but we want you to grow up to be a pro.