Sinceleaving school at age 16 to start his first business, Virgin Group founderRichard Bransonhas overseenhundreds of companiesand accumulated a fortune ofapproximately $5 billion.
The self-made billionaire could retire at the drop of a dime -- but retirement is the last thing on the 66-year-old's mind.
"I don't believe that retirement should be the goal,"he wrote in a recent blog post.