What goes up must come down

Life is full of ups, downs, turnarounds
it's part of growing up, part of life

Everything seems so hard, so tough
always convinced that your life is the worst

Supposedly what goes up must come down

When your life is turned around, flipped upside down because of one mistake,
the past, the good times, the fun times, fly away

When are you supposed to get them back?

What if you can't or they never do?