4. Challenge yourself. Albert Einstein once said, "One should not pursue goals that are easily achieved. One must develop an instinct for what one can just barely achieve through one's greatest efforts." Underestimating yourself and playing it safe hold you back from success. When you believe in yourself and your abilities, you often can go beyond the imaginable.

3. Exercise your mind. Just like your muscles, your mind needs to be exercised to gain strength. Growth and development take consistent work, and if you have not pushed yourself recently, you might not be growing as much as you can. Mental strength is built through lots of small ...