There's a line about Trump that resonates with me more than all the other 40m lines about Trump, and it came from the film-maker Michael Moore: "Trump is always lying, and he's always telling the truth. That's what makes him such a great performance artist."
Always lying, always telling the truth - you could see it after the impeachment "acquittal", when they contrasted the reaction of Trump to that of Bill Clinton in similar circumstances. Clinton was apologetic, at least in a formal sense. Trump ranted for an hour, venting his rage at all those who had crossed him.
Almost everything Trump said during this performance was factually inaccurate - he lied and lied about what he had done, and what he had failed to do. Yet in a bigger sense he was telling the truth. He was telling the world that he hated his adversaries in this matter - and he was going to do them down if he possibly could.
In all likelihood, in truth, that is roughly how Clinton was feeling too. But like most professional politicians, he wasn't going to share that with the multitudes, so he found a form of words that would get him out of there in a vaguely dignified way.
Always lying, always telling the truth - the good thing about it, is that you know where he's going with all this. At this stage, nobody should be in any doubt that Trump aspires to being a dictator, indeed that he is already doing many of things that dictators do, and evidently there's not much that anyone can do to stop him.
He's not hiding any of this - that's the truth he is always telling. The lies he is always telling are just the method that he is using to get there, arising unavoidably out of the fact that, as he put it on the subject of Ukraine, he is "only interested in corruption".
And even in this there is a kind of higher truth, because everyone of normal intelligence knows that he's always lying, and he knows that everyone knows he's always lying - so if you just turn it upside down you always know what the truth is.
If you want to, which a lot of people don't.
Which brings us back naturally to a Sinn Fein fundraiser in New York in 1995, attended by one Donald Trump, who allegedly didn't make a donation, which is probably the truth.
We will never know the extent of the meeting of minds that night in the Essex House hotel - there is just a famous picture of Gerry Adams shaking the hand of the honoured guest - yet at that stage, a few months before the IRA bombing of Canary Wharf, it was not Donald Trump who was always lying, and always telling the truth. Not in politics anyway.
No, the world leaders in that field were the Sinn Fein representatives - who would routinely be telling reporters after some meeting with the government that they would now have to bring this matter to the IRA - implying that the IRA were different people, which in any meaningful sense was a lie.
Indeed some of them would claim never to have been members of the IRA, which was Trumpian in the sense that everyone knew it was a lie, and they knew that everyone knew it was a lie, therefore it contained some kind of a twisted truth.
Always lying, always telling the truth - the larger truth in this case being that the IRA, or Sinn Fein, whatever they were calling themselves, were always quite forthright about their eventual ambitions.
Without needing to actually read their Green Book, you would know of their disdain not just for the state of Northern Ireland but for the "Free State".
Indeed it was that very disdain, or even loathing, that enabled them to tell so many lies about who they were and what they were doing - after all, why would you trouble yourself with factual accuracy just to oblige these miserable people who share none of your vision?
Yes, there were Sinn Fein supporters last week shouting "up the 'RA" and denouncing the "Free State", in what they felt were the closed gatherings in which they are able to fully express themselves. But really, no sane person has ever been in any doubt that that is where they are coming from, and that is where they are headed.
Really this was never some big secret that they were keeping from us.
And yet, even as they insist on talking about their United Ireland and other nationalist concoctions, you have commentators who somehow think they're only saying that for show. Commentators who are surprised to hear that Sinn Fein is still celebrating the doings of the Provos.
Which is a bit like reporters being taken aback to hear that Trump was interfering in the court case involving his good friend Roger Stone - which he denied doing, while insisting he would have been entitled to interfere anyway.
Again, always lying, always telling the truth - but even Trump might concede, that others have been there before him.
He's even had dinner with them.
A major theme of the election was that young people weren't voting for Fianna Fail or Fine Gael because they couldn't think of any reason why they should - and good on them, I say.
For decades, a substantial percentage of each generation of Irish people that came along was automatically programmed to vote for FF or FG without really needing a reason - maybe their fathers just told them to do it, or some other vague tradition drew them in that direction.
But I'm with the young people of today on this, because there has never been a time in my life when I voted for either party, or even remotely considered it - nor indeed will there ever be such a time.
It just isn't something that I could regard as a serious proposition, and indeed I wouldn't even do it as a joke.
I suppose there were others like me who reached a certain age and with a heavy heart realised that it was now their solemn obligation to vote for FF or FG, for some dubious reason or just for the feeling of backing a winner.
I never reached that age, or felt that obligation, or found that reason, or wanted that feeling - and now the young people are with me in large numbers.
Looks like the Diary was ahead of the curve on that one too.
While I welcome all contributions by Marian Keyes, not least because we are both graduates of the Rutland Centre, I wasn't totally on board with her recent assertion that she only reads books written by women, because men's lives are "so limited - it's such a small and narrow experience".
Writers in general, I have found, tend to be limited in their experience in any normal sense, which is perhaps why they choose to spend much of their lives sitting in a room all day, making things up as they go along.
I look to the great Mississippian writer Eudora Welty, who put it like this:
"I am a writer who came of a sheltered life... it would be interesting if I had been in jail or trodden grapes like other young people... I didn't even suffer early in life, except for my father being from Ohio..."
But there is something in Welty's career too which speaks to the larger theme of Marian Keyes, and to the exclusion of women from the canon - it is not known widely enough that in 1936 Welty wrote a story called Death of a Travelling Salesman.
It is so nailed-on that Arthur Miller lifted this title for Death of a Salesman, it's not even worth discussing.
And Welty's story was great too.