“Late Show with Stephen Colbert” decided to go live this week and next for both political conventions which -- in the scheme of late night TV -- is some kind of crazy. Everything can go wrong, or could, and almost certainly will. It’s a prescription for disaster, or worse, a prescription for crickets (“Late Show’s” last attempt at “live” following the Super Bowl as the best “cricket” example that comes to mind).

But Monday’s Colbert “Late Show” opener from the Ed Sullivan proved that “live” is something TV ( as it happens) is now especially well-equipped to handle, while also the perfect reset button for a TV program in search of resets.

“Late Show” has needed that and Monday happened to present the perfect opportunity, and one that came bearing gifts, lots of them, in fact. It was also a blast from the past, two blasts in fact, and a vivid demonstration of what late night TV would have been like at this very moment if TV’s two most effective political satirists hadn’t decided to take early retirement last year (not “early” for them, but early for fans). Both Jon Stewart along with the former Stephen Colbert (the right-wing pundit one) returned for one night only, reminding fans of lost opportunities and what might have beens. At least what they WERE Monday was funny and effective.

What made me laugh: Stewart’s spit take of course. Who doesn’t laugh at a spittake? Finding Stewart in a cabin in the woods -- a former host hiding away in a time capsule with the beard to prove it -- Colbert asks his old friend and mentor if he knows who the GOP nominee is. No, of course he doesn’t. Been hiding in a cabin the last year. Before getting the answer, Stewart asks to take a sip of “liquid” before getting an answer. We all know what’s coming.

Stewart, following his comic expectoration: “You mean ‘The Apprentice’? The guy who did a McDonald’s commercial with Grimace?

“The guy who filed for bankruptcy in 1991 and 1994 and 2004? (Colbert reminds him also of 2009)? Mike Tyson’s business adviser? That guy?”

A moment later the former Colbert -- “The Colbert Report” Colbert -- appeared alongside Stewart in the cabin, explaining that he too is living off the grid, and needs a quick update on the election. But first, he needed to take a sip, too ...

Colbert didn’t reprise merely Colbert but also “The Word” -- the word of this particular day was “Trumpiness.” You will recall a famous former word of the day -- “truthiness,” which designated something from politics that wasn’t necessarily “truth” but a general approximation of “truth,” or something a little closer in fact to “a lie.”

“Hello, nation, did you miss me?, asked “The Colbert Report” Colbert. Sure have.

What didn’t work: Colbert’s “live” opportunity was squandered in one obvious way. The Melania Trump “Didn’t Michelle Obama Have a Remarkably Similar Speech Eight Years Ago?” moment from Monday dominated Tuesday’s internet mindhive, but Colbert made no mention of it in his opening monologue. The controversy was comedy gold, but this vein went untapped, which is another obvious risk with “live” -- you might just miss out on what everyone else is talking about. (“Late” live also overlooked a few other obvious moments -- RNC opening night speakers Willie Robertson, Scott Baio and Antonio Sabato Jr. Can’t win ‘em all).

In fairness to Colbert, the Melania controversy didn’t break until much later, long after the live show. Maybe he’ll pick up this nugget of gold on Tuesday’s edition.