Working hard, hardest or fooling oneself

Here's an interesting take on why some talents don't prepare and execute to the fullest of their potential.

It seems a bit too simplified. Some don't know they aren't working hard -- they actually think they are, but aren't.

For some others, it just seems to be flat out not caring enough but delving into the reasons for that would require the length of a college thesis and a specific look at each individual to glean the reason(s) why.