The important thing is not to be bitter over life's difficulties. Learn to let go of the past and recognize that everyday won't be sunny.
And if you find yourself lost in darkness and despair, remember - it is only in the black of the night that you can see the stars and those stars will lead you back home.
So don't be afraid to make mistakes, to stumble, to fall. Because most of the time, the greatest rewards come from doing things that scares you the most.