Onlookers from around the world are baffled that an arrogant, self-serving blowhard like Donald Trump could win the Republican Party's presidential nomination. During last week's Democratic National Convention, President Obama admitted, "People outside the United States do not understand what's going on in this election. They really don't."

But John Oliver has a theory explaining Trump's success. On the latest episode of Last Week Tonight, he explained why The Donald gets away with saying horrendous things on a daily basis.

"He has clearly said countless awful things through this campaign. Any of which would disqualify any other candidate," Oliver said. "Just this week, he declined yet again to release his tax returns, lied about getting a letter from the NFL agreeing with him that the debates shouldn't clash with football games, called Angela Merkel a moron, implied that Brazil brought the Zika Virus upon themselves, and encouraged a foreign powers hack of his political rival."

Then Oliver threw us a curve to emphasize just how awful Trump's actions are.

"Now, two of those [things listed above] above didn't happen. But you're not sure which two. And that's kind of the point, isn't it? Because Trump hasn't said one crazy thing. He's said thousands of crazy things, each of which blunts the effect of the others. It's the bed of nails principle. If you step on one nail, it hurts you. If you step on a thousand nails, no single one stands out, and you're fine. That is how Donald Trump has managed to say pretty much anything in this campaign, seemingly without consequences."

But Oliver argues that Trump's definition of "sacrifice" is by far the most disturbing thing to come out of his mouth yet. Check out why in the video below, which also offers a recap of last week's DNC.