Benjamin Graham
When studying at Columbia University, Buffett met Benjamin Graham, a professor. Buffett became very involved in Graham's theories and became very close with Graham. Graham adopted the role of being Buffett's mentor and a major influence in his life when it came to finance and investing. Once Buffett graduated from Columbia, he applied for a job at Graham's investing firm, but was shot down. Buffett then returned to Omaha to continue working for his father, but in 1954 Graham decided to hire Buffett. Warren Buffett continued working for him until Graham made the decision to shut down his business. If it wasn't for Graham, Buffett probably wouldn't have had such a big impact and be as successful (Warren E. Buffett).