I loved this when I saw it. A lot of the time it is our mind set that holds us back, rather than the circumstances in which we find ourselves. When you are low, make a mental or physical list of the good stuff you have going on. If you are lucky enough to look out of a window and see a beautiful sky, or hear a bird singing, that is something to be happy about. Look with eyes that find the beauty, not with eyes that see only problems.
(Picture from Pinterest)