The most amazing thing about Monday night's Q&A: that rockstar physicist Brian Cox had agreed to come back, given what happened last time.
It was August 2016 when the brilliant, charming Brit last appeared, along with fellow panellist Malcolm Roberts, the erstwhile One Nation senator.
As we noted at the time, this resulted in "the national embarrassment of [Cox] having to put his eyes back in their sockets over and again as Roberts threw one conspiracy theory at him after another. When eyes weren't popping, they were rolling. Other panellists were aghast. Even host Tony Jones felt moved to clarify things in stark terms."
On Monday night, no one had forgotten that insanely memorable occasion, with host Tony Jones riffing off the memory early on.
"Brian, I said in the promo, with your long search through the universe for aliens, you never would have imagined finding so many in the Canberra parliament?"
Cox: "Last time I was on here, I didn't know Malcolm Roberts was a fellow Brit. I might have been nice."
Jones: "You did treat him like he was an alien."
Indeed Cox did, and on his return it might have seemed he was back again on the alien planet - a planet hosting a parliament that appears to have an unstoppable ability to pitch forth conundrums barely comprehensible even to one of the great brains of the age.
On this occasion there was no one of the quality of Malcolm Roberts present to boggle and baffle the mind, but there was plenty of head-scratching on offer - the question of citizenship first out of the gate and summarised perfectly in the opening question.
"Do the pollies take the public as total mugs?" wondered audience member Peter Johnson, who said he had considered standing for the Senate but decided not to once he became aware of the constitutional bar on dual citizenship.
"If a mere mortal such as me is aware of the relevant laws, how on earth can it be that politicians failed to even ask questions of their parties and the legion of cronies and so-called political advisers? They all knew, or should have known, for years and kept it as their grubby secret. When will any, just any, of our elected representatives of any shade finally and genuinely respect rather than show utter contempt for the people to whom they are supposedly accountable?"
Peter Johnson surely spoke for a cranky nation. From the pollies on the panel, he got platitudes and some pointy argy-bargy as the Coalition's Angus Taylor and Labor's Terri Butler went at it.
Taylor conceded "a breach of trust", and offered: "It's been disappointing to me that that hasn't happened as quickly as it should have." And then he went the biff: "I still feel as though Bill Shorten is hiding dual citizens in the basement."
It wasn't clear whether he meant this as a compliment in comparison to the Government, which has been hiding its dual citizens in plain sight, but Labor's Butler wasn't having a bar of it. "We don't have anything to hide because our processes sorted this out before people ran. You guys ignored."
It was here that Brian Cox was invited to contribute, in the knowledge that Roberts, his tormentor from last time, was one of those undone by the dual citizenship mess.
One imagines he'd had plenty of cause to wonder why Roberts had not been barred from the Senate for reasons more sensible than this, but on the specifics of the matter he confined himself to understatement: "It's an unusual thing."
Unusual it is. So unusual that Tony Jones wondered if extreme measures weren't required.
"Angus, wouldn't it be the easiest thing for the Governor-General to step in, dissolve parliament, and instead of having a series of staggered by-elections that go for a long time in next year, just have an election and resolve everybody at once?"
Taylor: "I don't think the election resolves the issue. What resolves the issue is people 'fessing up on their citizenship."
Jones: "But once they do, we could be eight or nine people down the track."
Taylor: "Let's see. But that's what has to happen."
Butler: "We have to deal with not just citizenship but deal with the standards of conduct people engage in public life."
Jones: "Should there be an election?"
Butler: "I think there should be, actually. I think that's pretty clear. It does resolve this because nobody is going to be silly enough, I wouldn't have thought, to run for the next general election...
Jones: "Would you as a Labor MP be happy to see the Governor-General step in and dissolve Parliament?"
Butler: "I don't want to see a dismissal. That's not what I'm advocating for. Any Labor MP would be horrified by the vice regal representative in Australia coming in and dissolving the government but Malcolm Turnbull could do the right thing and call an election."
And suddenly, here we were back in 1975. Next time, perhaps Brian Cox can explain time travel.