I feel sorry for cadets who start that young. Some of my friends who started that young and are now in their mid-forties are totally bored with flying but have no skills to try anything else. All they've got in front of them is another twenty years of the same. I didn't start professional flying until 40 and am still loving every minute of it. I also have forty years of very varied and interesting life to look back on and draw on in the future should I decide to stop flying one day.