Is your life controlled by you or by forces outside yourself? Those with an internal locus of control feel that they have choice in their lives and control over their circumstances.
They tend to feel happier, less stressed and are more satisfied with life in general. Those with an external locus of control feel more at the mercy of external events. They tend to be more susceptible to depression as well as other health problems.
Focus your efforts on the things in life that you have control or influence over instead of perplexing over things that you don’t.