Aria,
I don't mean that it is arrogant to think you can become a pilot at 19. Some start at 17. I mean it is a bit cocky to think that you will be such an impressive 19 year old among all those older applicants, that NetJets will pick you for the cadet programme. Several people who have been to Stage 3 have reported in this thread what age range they saw there. I just think it's a bit dreamy to think you'll somehow fare better just because you want it badly. If you can't wait, by all means start now, but it won't likely be with NetJets on the cadet programme.