Hiya,
Just wanted to put my 'two penneth' worth in. I work for a UK charter airline and they, along with most of (if not all) of the other charter airlines in the UK have a minimum age limit of 20 years old.
I went for my first interview when iI was 19 (this is the minimum age with Virgin Atlantic) and didn't get through. I then waited till i was 20 and tried with my present company and got the job, and nearly 7 years on i'm very happy.
I think what im trying to say is that the airlines here in the UK obviously consider 20 to be a suitable age to become a flight attendant.
Keep trying to get your dream job Mikey as it would seem you have what it takes!
Cheers
Jennitaylier