What is success?

"Success isn't destination, it's a journey. Everybody working to get to the top but where is the top? It's all about working harder , getting better, and moving up and up". Thought one of the biggest and popular singer in US.
Why on a journey not a destination? i personal confuse about that! some people have different definition about that. In a destination failure isn't fatal, and success isn't final, it's the courage to continue that counts.