As children, our parents (or other adults) are smart, kind, and fit perfectly in the big world. They are our idols and masters - our superheroes.
As teenagers we start to notice things though; Cracks in the armor of our parents, slips of the tongue, clumsy mistakes. As these occurrences pile up you realize they are human, just like you.
In young adulthood we may start to notice some characteristics where you have to flat-out entertain the idea that some of their weaknesses are your strengths. They've gone from superhero, to a flawed-superhero (what superhero doesn't have weaknesses?), to human... but now you have some superior characteristics?
This is contradictory to our classic view of our parents; it is difficult to reconcile the superheroes of our childhood with newly discovered categorical flaws.
In 25 years you go from helpless god-servant to transcending your superhero. [note that the movement from defining parents as gods to superheroes deserves its own intellectual moment]
Neither the child nor the parent should feel anything but happiness with each passing stage.
"Most people in most countries have been doing steadily better in human development. Advances in technology, education and incomes hold ever-greater promise for longer, healthier, more secure lives."
This can show even between single generations.
The parent should not be offended, but proud that their offspring are better versions of themselves. The child should be humble, but not apprehensive about breaking the parental superhero - it is a natural and positive adventure.
This is somewhat of a dangerous subject - especially for the overconfident, rebellious, and zealous young mind:
Keep in mind the pure folly in comparing oneself to another. This thought-experiment is not to encourage this behavior as it is purely destructive - it is to acknowledge the cognitive dissonance occurring in the minds of the growing youth.
Great people have humility and do not overstep the parent-child relationship. This is not a tool to be used to break chains, but to evolve as an adult.