CNBC's Jim Cramer knows that part of smart investing is learning from everyone.
So when Carlyle Group co-CEO David Rubenstein said that the only thing he's worried about for the next two years is some sort of unexpected geopolitical event, it got Cramer thinking.
"The only thing we have to worry about, I think, in 2018 and 2019 is some unanticipated geopolitical event, the so-called black swan," Rubenstein told CNBC's Net/Net dinner in Washington, D.C. on Tuesday.
While Cramer doesn't like the phrase "black swan" because he wants to be ready for anything and everything, he did compile a list of 10 concerns he has going into 2018.
"A black swan is the thing you don't see coming, but we've got more than enough concerns that can be anticipated," the "Mad Money" host said. "Let me tell you what weighs on me every day."