Fr3d,
A lot of people start pilot training for the wrong reasons, mainly in it for the glamour and not for the love of flying.
In the USA, on average, 70% does not finish their PPL training.
Being able to pass written exams and flight tests does not garantee that you have the 'right stuff'.
The right combination of personality, perseverance, character and just plain stupid luck.
Going to a "well known" school is no additional guarantee in itself either.
Unless it's maybe an airline owned academy.