Why Does Trump Conceal What he Discussed With Putin?

The statement above is Donald Trump's reaction to a Washington Post story about the abnormal secrecy Trump has imposed over his one-on-one meetings with Russian strongman Vladimir Putin. Of course it is a LIE! There are no transcripts of these meetings, and Trump has even asked for the translator's note's (and forbid her from talking to anyone about the meetings).

No one (but Putin and Trump) knows what was discussed in those meetings, and we only have Trump's word that no treasonous actions took place. The American people don't know what was said. The American (and world) press doesn't know what was said. Congress doesn't know what was said. Our intelligence agencies don't know what was said. And even the senior staff at the White House doesn't know what was said.

Why the extreme secrecy? Shouldn't the senior White House staff, the Congress, and our intelligence agencies be privy to those discussions at the very least? What is Trump trying to hide?

This brings back a question that many (including me) have wondered about since Trump was sworn in (and began his Russia-friendly statements and actions) -- What does Russia (Putin) have on Trump?

Is it Trump's financial ties to Russia (which Trump has denied while his sons have bragged about)?

Is it that he helped the Russians to launder money through his businesses and properties?

Is it because the Russians have evidence of his collusion with them regarding the 2016 election?

Is it the embarrassing "pee tape" the Russians could reveal?

Or is it something else that could be revealed that no one knows about yet?

There is something, and Trump's desire to keep his discussions with Putin strictly secret would seem to point to that something being serious enough to damage or destroy Trump's presidency.