It's interesting (not to mention frustrating) how, as human beings, we want what we don't have and don't want what we have? For the most part i'm pretty content with my situation, but there are some areas in which I wish I was in a better place. It's easy to begin focusing on those wishes, ignoring that which we possess and should be grateful for.
I won't go into detail here, as much of my personal struggle is just that...highly personal. Just a thought. As soon as I improve in an area, I immediately see three areas in which I'm not happy with myself, the situation, whatever. And not in a "constantly driving to improve" sort of way, where that dissatisfaction leads to motivation. More of a feeling of hopelessness because I'm not where I want to be and it seems so far to the desired destination.
In some cases, the dissatisfaction has led to apathy, which has in turn led to major life issues. Again, not going to go into detail, but sometimes you look at a deficiency you have and it seems so insurmountable. The feeling that there's nothing you can do prevails. And all you can bring yourself to do is think "I wish...".