Larry Cebula:
This is not because you are not bright enough. You are plenty bright. In any case, finishing a Ph.D. program is more a matter of persistence than intelligence. The reason you are not going to be a professor is because that job is going away, and yet doctoral programs continue to produce as many new Ph.D.s as ever. It is a simple calculation of odds—you are not going to win the lottery, you are not going to be struck by a meteorite, you are not going to be a professor. All of these things will happen to someone, somewhere, but none of them will happen to you.
Mom, this is why I didn’t go to grad school and try to become a professor.