For reasons that everyone knows entirely too much about, television nearly lost “Two and a Half Men” last spring. One of the cast members had personal problems in a broadly public way, the eighth season was halted, and a merciful cancellation seemed possible for the highly rated CBS sitcom.

When all is said and done (and former co-star Charlie Sheen is roasted and toasted and given whatever glories await him) — and now that Ashton Kutcher proved Monday night on the show’s ninth-season premiere that almost any sentient being could have easily joined the cast — the thing I’ll remember most about this saga is that no one besides the people who make money off syndication bounties ever seemed terribly distraught about losing “Two and a Half Men.”

Where were the hard-core fans, the sort who keep detailed episode guides and recaps, fretting over the show’s demise? Where was the letter-writing campaign? Where was the panic about how it all ends, and what would happen next, and how all the writers would resolve all the complicated story lines?

Well, of course, we know better than that. There are no complicated story lines. There was never anything in this show to think about, which is why it’s such a hit. It’s the show your Nana watches so she can pretend to be shocked by all the jokes about just-tawdry-enough sexual escapades. It’s misogyny and promiscuity made all giddy and giggly.

And with Kutcher as its new co-star, “Two and a Half Men” demonstrated just how uncomplicated it is.

Monday’s premiere picked up at the funeral for now-deceased Charlie Harper (Sheen), who we learn was hit by a subway train and “exploded like a balloon full of meat,” according to the possibly psychotic woman he’d run off with in the middle of the last season. Thus the casket was closed; Charlie’s presence was indicated by one of his beloved Nat Nast camp shirts and a bevy of bimbos who had come to his funeral, if only to bitterly recall the venereal diseases he’d given them.

(“Nana, why is the TV on so loud?”)

(“Don’t switch it off, I’m watching it!” Nana shouts from the other room. It seems like wherever Nana goes, “Two and a Half Men” is on.)

Home from the funeral, Alan Harper (Jon Cryer, regarded by many to be the most patient co-worker in Hollywood) learns that his mother intends to put Charlie’s Malibu, Calif., beach house up for sale — the principal setting for “Two and a Half Men,” where eight seasons ago, Charlie offered Alan and his son, Jake (Angus T. Jones), a place to stay.

Oh, they stayed. They stayed as Jones grew from precocious sitcom tot to rotund adolescent to a young man who, if circumstances had been different, might appear in the background of a Disney sitcom about girls who text a lot.

“Two and a Half Men” is never too funny, never too odd, never too naughty. Again, this is why it’s on in hospital lounges and the waiting room at the oil-and-lube.

There’s always one moment in every show, though, where all is golden. On Monday’s episode, this moment came slightly before Kutcher’s grand entrance: When the beach house goes up for sale, John Stamos (from, well, everything) drops by for a look, staying only long enough to make the episode’s requisite obliquely homophobic joke.

He is followed by Jenna Elfman and Thomas Gibson, a.k.a. “Dharma and Greg” — a nice family-style nod to “Men’s” co-creator Chuck Lorre, who also co-created that show way back when. It was worth watching this episode of “Two and a Half Men” just to discover that Dharma and Greg appear to hate each other and are trapped in a loveless marriage.

Finally, Ashton. He shows up wet and frantic at the patio door and, to sustained war whoops from the studio audience, enters the no-fourth-wall realm that originally made him, years ago on “That ’70s Show.” Full circle, with better pay.

His character’s name is Walden Schmidt. His wife dumped him, and he tried to commit suicide by hurling himself into the Pacific. But Alan (and, presumably, Jake) will save him, providing him a sense of home and brotherly care. Handily, he is worth $1.3 billion in computer-software riches. Instead of drowning himself, Walden drowns between two women he and Alan meet at a bar.

The next morning, Berta the housekeeper (Conchata Ferrell) discovers that Walden likes to walk around naked. Alan’s ex-wife (Marin Hinkle) sees his naked splendor, too, and so does Jake. It’s a massive endowment, and they aren’t talking about syndication fees. Though maybe they are.

In any case, Nana, prepare yourself for unlimited jokes about Walden’s wand.

Two and a Half Men

(30 minutes) airs Mondays at 9 p.m. on CBS.