Billionaire T. Boone Pickens's final message before he died

In a final message written shortly before he died, T. Boone Pickens shared the lessons he learned on how to succeed in business and in life. The billionaire passed away on September 11 at 91.

Pickens said he credited his success to his ability to take responsibility for his mistakes.

The oil magnate also encouraged his followers to be generous with their money.

Visit Business Insider's homepage for more stories.

In a message he wrote shortly before dying, legendary oil magnate T. Boone Pickens recalled the lessons he learned on how to succeed in business and in life after nearly a century on Earth.

The oil prospector died on September 11 at 91. Pickens made his billion-dollar fortune after founding oil and gas company Mesa Petroleum, and later started the hedge fund BP Capital Management.

Pickens wrote a letter on the lessons he learned over the course of his professional life, recently released by the T. Boone Pickens Foundation. Chief among them, Pickens said to take responsibility for your own failures (and successes). Recalling his grandmother's advice, he said he never blamed other people for his mistakes in the 50 years he ran his business.

Read more: Oil tycoon T. Boone Pickens has died. Here are the lessons he used to guide his career.

“My failures？ I never have any doubt whom they can be traced back to,” Pickens wrote. “My successes？ Most likely the same guy.”

He addressed the letter to his “followers” — 1.9 million on LinkedIn and 145,000 on Twitter, the latter which he credits to a viral “feud” he had with the rapper Drake in 2012.

The billionaire also wrote that he aimed to be as generous as possible with his wealth during his life. The philanthropist donated his money to various Republican politicians, plus the University of Texas Southwest and Oklahoma State University. In 2010, he signed The Giving Pledge alongside Bill Gates and Warren Buffett, promising to give his wealth to charity after death.

“I liked knowing that I helped a lot of people,” Pickens said. “I received letters every day thanking me for what I did, the change I fostered in other people's lives.”

Pickens said he amassed his wealth due to working hard, not cheating, adeptly analyzing risks and rewards, and learning from his mistakes.

“I left an undying love for America, and the hope it presents for all,” Pickens wrote. “I left a passion for entrepreneurship, and the promise it sustains. I left the belief that future generations can and will do better than my own.”

You can read the rest of his letter and a list of his best advice on LinkedIn.