Even financial gurus like Warren Buffett, CEO of Berkshire Hathaway Inc., are not immune to making mistakes or bad investments. Buffett has acknowledged a costly “mistake” that impacted the conglomerate’s financials. Despite earning $42.5 billion in 2020, Buffett revealed in his annual letter to shareholders that the company had incurred a substantial loss of $11 billion because of an ill-fated acquisition. Don't Miss: Why Jason Calacanis and Other Silicon Valley Elites Are Betting On This Start