The people who've answered already give an interesting range of responses which start to paint a picture.
I would not begin to interpret the picture specifically without having dialog with the respondents.
What I hear in general seems to do with attitude towards life and beliefs about oneself.
Without judgment, when I have been a caregiver, I have seen a victim mentality in some people with chronic illness that loomed larger in their minds than their interest to make lifestyle changes. Others with greater challenges have re-made themselves by means of their resolute will and unquenchable spirit.
I once asked a friend what he wanted in life. He told me about his dreams for more education and training, to advance in his work field. I asked him, "What prevents you?" and he answered, "Laziness."
What I appreciated about his response was the honestly. He knows he has an issue with procrastination.
A few weeks after this, he took some big steps towards getting the education he desires. Maybe it just needed the provocation of self-awareness, coming from him and spoken to a friend.
I have seen others with much talent who just seem unable or unwilling to test themselves outside their comfort zone. As a guess, in the instances I am thinking of, they may be unwilling to be seen as less than perfect and are unwilling to take a chance which could result in "failure."
My life, especially since making a change in 2000, has been one of taking risks and relishing adventure, exploration and every opportunity to learn and grow. Still, there are some habits I haven't fully addressed yet. No excuses!