are there any "Billion Dollar agents" out there

It is my goal to sell a Billion Dollars worth of Real Estate during my tenure as a real estate professional.  My best friend, and a fellow agent tells me that it cant be done.  I am betting him there is someone out there.  Does anyone know anyone.  I will do about 20 million this year.  Great number but at that pace it would take 50 years.  IT will take 20 back to back 50 million dollar years... Wish me luck.  Would love to hear of anyone that has done it.