Up and down, up and down.  This is the way of life.  You could also, instead of a sine wave, see the unfolding of life as a circle:  round and round, round and round.  This is flow.  This is how things unfold.  The peaks and valleys do not have to be so high.  Beneath all of it lies peace.  What goes up will come down.  This too shall pass.  There is a reason you are familiar with these phrases.  Do not lose hope when in a valley.  Do not cling to the highs.  Instead, flow.  Experience.  Just be.  Observe and participate … all in, but not thrown off balance, aware that this is Life in all of its fullness, and the more you participate instead of shying away from certain experiences, the more you will feel the Joy that is also beneath it all … the pure Joy of being Joy in Expression.  You are so very loved!