Warren Buffett said in his letter that his company's record tax payment should be used to "take care of the many who ... get the short straws in life."

The 94-year-old Buffett also acknowledged his advanced age in his annual letter, telling shareholders he now uses a cane and will spend less time fielding their questions at Berkshire's annual meeting in May.

Warren Buffett started what would become the most profitable investment in his legendary career. Through his company, Berkshire Hathaway Corp. (BRK.A), he began accumulating shares in Apple Inc. (AAPL),