(CNN) Fresh off a disastrous news conference with Vladimir Putin in Helsinki, President Donald Trump took to Twitter to tout how successful his two-hour-plus meeting with the Russian President had been.

"While I had a great meeting with NATO, raising vast amounts of money, I had an even better meeting with Vladimir Putin of Russia," Trump tweeted Tuesday morning. "Sadly, it is not being reported that way - the Fake News is going Crazy!"

What made the meeting so great? What was discussed? What was the mood? How well did the two leaders get along (or not get along)? Where were the points of agreement or disagreement?

We don't know the answer to any of those questions because the Trump-Putin meeting was a one-on-one affair , with only translators for each man in the room. There is no official readout of the meeting. Nothing but any notes Putin or Trump took, their memories and the memories of their translators. And that, apparently, is how Trump likes it.

There's any number of problems with this approach to diplomacy -- particularly with a leader like Putin. Here are the two big ones:

1. It allows both sides to tell their own version of what happened without concern for what actually happened.

Without anyone other than Putin, Trump and the translators in the room, there's simply no way of getting anywhere close to a definitive account of the meeting.

Putin is already shaping his version of events , telling state TV in Russia after the meeting that the two men talked about Syria, Ukraine and "Russia's mythical interference into US elections."

Russian Foreign Minister Sergey Lavrov also threw in his two cents about the meeting after it concluded, noting it went "better than super."

Is that right? And if it went "better than super" from the Russian perspective, is that a good thing for the US? Who knows!

Members of Congress have said they'd like to call Secretary of State Mike Pompeo and others on Trump's national security team to the Hill to testify about what exactly happened in that meeting.

"I think we need a read out on if there was any agreement," Republican Sen. Lindsey Graham told reporters Tuesday. "I don't mind meeting with our adversaries. Russia is definitely an adversary, but I want to make sure we're being informed as to what potential agreements were made and whether or not and whether or not we think in Congress it makes sense."

Democratic Sen. Mark Warner put it this way: "What I'm deeply concerned about, and warned the administration beforehand, was what happened in this one-on-one setting. If the President was willing to dismiss American concerns in public, what in the heck did he say in private?"

But it remains to be seen if Pompeo will comply -- and remember that even if Pompeo *does* head to the Hill, he is passing on what Trump told him about the meeting, not what he himself heard in the meeting. Because he wasn't in the meeting.

2. We now have to rely on two unreliable narrators.

Both Putin and Trump have shown an affinity for bending -- and breaking -- the truth when it suits their needs. That's never a good thing, but it's a really not good thing when they are the only two people (aside from the translators) who know what really happened in that room. And when the geopolitical fate of the world rests, at least in part, on what transpired between the two men, that's worrisome.

Even if Trump and Putin weren't shaping the truth to suit their political and policy needs, the sheer challenge of remembering every in and out of a two-plus hour meeting is daunting. Think back to the last two-hour meeting you were in. If you didn't take notes -- and reportedly Trump did not have a notepad/pen, while Putin did -- how well do you think you would recall all the details of that meeting?

Hell, I take notes in my meetings and I struggle to remember what every line or jot means or refers to.

All of which brings me back to this: Was the summit "even better" than Trump's NATO meeting? We have absolutely no idea. And we never will. And that is a bad thing -- whether you love Trump or hate him.