Yaakov Blau shares his observation that some students who show tremendous potential in high school do not live up to that potential in later life. I have no doubt that this is true.
At the same time, my experience is that many high school students who show little drive and interest in their studies become inspired later in life and grow into significant leadership positions in Torah and in other fields.
Perhaps we must conclude that success (or lack of such) in high school does not indicate success in life.
Abie