President Trump speaks at a reception for senators and their spouses in the White House on March 28. (Jabin Botsford/The Washington Post)

President Trump flat-out admitted in an interview with the Wall Street Journal that the North Korea-China situation is more complex than he thought it was. He says he reached this conclusion after speaking directly with Chinese President Xi Jinping.

“After listening for 10 minutes, I realized it’s not so easy,” Trump said.

But this isn't the first time that Trump or his staff members have pointed to the steep learning curve that their novice-politician president is facing. From North Korea to health care to treaties to his own duties, Trump at several points has either acknowledged his ignorance or made it abundantly clear to his staff (who then informed your humble news media — anonymously).

Below are eight examples:

1. The North Korea situation is 'not so easy'

April 12: “After listening for 10 minutes, I realized it’s not so easy. I felt pretty strongly that they had a tremendous power” over North Korea. “But it’s not what you would think.”

2. Health care is 'unbelievably complex'

Jan. 27: “It's an unbelievably complex subject. Nobody knew that health care could be so complicated.”

3. The size of the job of being president

Feb. 7 via Fox News:

BILL O'REILLY: What surprised you?

TRUMP: I think the size, the magnitude of everything. So, I was a very big real estate person. I build a building for $500 million or $900 million. And here, you look at an airplane contract where you can save $600 million on 90 plans. I saved more than $600 million. I got involved in negotiation on a fighter jet, the F-35. And by the way, Lockheed Martin, a great company. But they weren't bringing their price up. I got involved, I saved more than $600 million as their (INAUDIBLE). But the magnitude of — you can do that at every level of government.

4. That government can't be run like a business

Feb. 10 via Politico:

In interviews, nearly two dozen people who’ve spent time with Trump in the three weeks since his inauguration said that his mood has careened between surprise and anger as he’s faced the predictable realities of governing, from congressional delays over his Cabinet nominations and legal fights holding up his aggressive initiatives to staff infighting and leaks.

5. What the New START treaty with Russia was

Feb. 9 via Reuters:

When Putin raised the possibility of extending the 2010 treaty, known as New START, Trump paused to ask his aides in an aside what the treaty was, these sources said.

Trump then told Putin the treaty was one of several bad deals negotiated by the Obama administration, saying that New START favored Russia. Trump also talked about his own popularity, the sources said.

6. How much his administration is cutting regulations vs. cutting taxes

Jan. 23: “A bigger thing, and that surprised me, is the fact that we are going to be cutting regulation massively.”

7. That he got to hire his entire White House team

Nov. 14 via CNBC:

A source told NBC News that Trump asked President Barack Obama during their Thursday meeting how many White House staffers he could replace. And when the sitting president responded that Trump gets to staff just about the entire White House, the president-elect was surprised, NBC's source said.

The Wall Street Journal reported a similar anecdote, but said that it was Trump aides who seemed “unaware” that the West Wing staff needed to be replaced after Obama's departure.

8. That presidents aren't subject to conflict-of-interest rules

Jan. 11: “I didn't know about that until about three months ago, but it's a nice thing to have.”