Who said it and it what context?
A few things to consider in the mean time....
Before a college teacher convinces you that exceptionalism is a bad thing, consider what the alternative might be and how that alternative might adversely affect you and your future.
If you have the ability, desire and wherewithal to become exceptional, wouldn't you work towards those ends? In other words, if you knew that you can pull a 4.0 GPA, are you gonna stand down, not study and strive for a 2.5 GPA?