Jim Rohn (Sept 1930 - Dec 2009) was one of the most well-known speaker in the business. He was actually Tony Robbins' first mentor. He as also helped influence other famous speakers such as Brian Tracy, Mark Victor Hansen, and Jack Canfield. He is very big on teaching the fundamentals. As he says in many of his audio programs, it's all about fundamentals.
One of my favorite quotes from Mr. Rohn is, "Success is nothing more than a few simple disciplines practiced every day. Failure is noting more than a few errors in judgment repeated every day." He has a unique speaking style. His teachings are simple yet profound. He will be missed.
You can visit his site at www.jimrohn.com. Here's a video of him explaining how if you want things to change, you must change. To have more, you must become more. Don't wish for less problems, wish for more skills.