How Much Success Is Enough?

So, question...how much success is enough to effectively motivate someone into developing new patterns or lifestyle?  I find that I am incredibly motivated by a successful experience, positive reinforcement, praise, recognition from others in a position of superiority... A single experience where I am negatively-criticized, put down, or made to feel wrong, inadequate, or inferior can drastically un-motivate me and cause me to not want to continue working with that person or toward the original goal.  Some people find failure, the thought of failing, or criticism from others to motivate them, to inspire some sort of personal competition to prove others wrong and be better than people expected.  I am the type of person that shies away from something if I think I'll fail or if people will judge me.  If I am currently procrastinating or putting something off or not experiencing a type of success it's easy to just continue in that flow.  However, for me, it's easy to build on positive experiences, and gain confidence, inspiration, and motivation from success.  But how much success do I need to stay motivated, to change my lifestyle, to stop procrastinating on things or take more initiative in certain areas of my life?