The smallest candle of light can make the biggest difference in the darkest of places. The answer, of course, is that he has a sense of Purpose and Hope. The Purpose is there, yet it cannot be seen. This doesn't mean that they are weak nor any less of a person, just someone who has temporarily wandered off their path to Purpose, and momentarily can't see their way out of the forest. For this reason, it important that we try to focus our attention on the positive.
Positive action destroys the thoughts of dispair that depression brings forth.
This is true just as deciding to walk in an unknown forest until you find the pathway out, destroys the hopelessness of being lost. And Hope can be created by taking action and finding one's Purpose in life. In every negative, there is a positive. The important thing which matters is that you are trying to grow and reach your goals. I commend you for the positive attitude that I have observed in your words.