This was one of the hardest lessons for me to learn. What I wanted for my son and how I thought his life should go was to much about what I wanted. We as parents want the very best for our kids, we have hope and dreams for our kids but they are OUR hopes and dreams, not our kids.
I know my son has such high potential and could achieve much in his life but he has no interest in progressing forward. I don't like it but have learned to accept it.
I think this can be a coping mechanism. To stay at a level of comfort opposed to putting in the effort to achieve something only to fail at it. If one says they can't do something then there is no threat of failing. I think the fear of failing and being a disappointment not only to themselves but also to their parents can keep them from trying.
This is a good thread and some really awesome responses.