One of the ways many people become successful is by approaching every crisis as an opportunity — to learn, to invest, to grow. Take billionaire business guru Warren Buffett. He once famously advised investors to be “fearful when others are greedy, and greedy when others are fearful." He has come through the worst of the pandemic not only richer — his net worth passed the $100 billion mark in March, even as he donates billions to charity — but with some valuable lessons for his fellow investors.