Even the rich and famous got taught some financial lessons during the Lehman Brothers bankruptcy period in Sept. 2018. 

"People that I knew had their lives devastated by these bankers who were not thinking about America and lying and selling crap," Kiss front-man Gene Simmons recalled in an interview with TheStreet.

Simmons said one key lesson from the meltdown is that investors have to spread the risk around or diversify. 

Here's what Simmons said about Tesla (TSLA - Get Report) CEO Elon Musk.