Up days and Down days. Does everybody have them, if so what do you feel is the cause?

Many/most days, my life is a life of sunny skies and good times, and just to be out in the world is a gift for me to enjoy every moment of.

Other times, my life seems empty, and very drab, and sometimes not worth living, and I tend to see the down side of just about everything and everybody.

I have spent time to examine the why's and what for's of those down days and wonder if it is "chemical' or lack of some lack of chemical in my brain that causes those kinds of depressed feelings.

When I ran and competed in the local 10k and 5K races, and ran with a team with Fluor Engineering, I was on top of the world ALWAYS, mentally and physically. A friend suggested that it is probably the result of the Endorphins released into the brain along with the hard physical exercise of racing.

Another friend suggested that it may be due to my finding 'an area of success' i. e. running/racing, that gave me 'an area of success" in my life, and the is what may keep me emotionally buoyed' up.

Does anyone else have these kinds of emotional ups and downs and if so, what do you attribute it to?

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I would like to hear only from those who experience the roller coaster ride of ups and downs. If not, please hold your responses
Up days and Down days. Does everybody have them, if so what do you feel is the cause?
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