Pro it will happen. My son just graduated UCLA dental school and is now doing his residency in orthodontics at UCLA and will graduate June 2019 at the ripe old age of 28! Your son will achieve his dreams before 30 also. What a blessing that they are focused and know what they want to do so they don't waste time by changing majors. I always told my son consider it a prison sentence but when you get out...there will be a goldmine waiting for you! Congratulations again!!