I don't know the key to success, but the key to failure is trying to please everybody.
Our world is filled with critics-well meaning (usually) parents, sibling, spouses, lovers, friends, coworkers, bosses, and mentors who think they can neatly pinpoint our deficits and prescribe appropriate treatment. They seem to know what we're doing wrong with our lives and have a good idea of what we ought to do. But, we can listen to the the most important and credible people in our lives without becoming unduly influenced by them.
We need to stay true to ourselves, however, and this is crucial. It prevents us from being torn a hundred different directions and losing ourselves in the process.