I was 19 when I started out at the college with NATS. Although the majority of people starting out are in there 20's, starting out earlier will not hold you back. Remember though that unfortunately not all of our trainees make it through the training system and it may be worth considering if a degree may be useful for your future employment if you were one of the unlucky ones that don't make it. Your education, like already said no mater what the degree is in, will however not make any difference to your ability to succeed in the job. Best of luck whatever you choose to do.
WTF