Yet some shows build this sort of flimsy fakery right into their premise. The opening credits of Ben and Kate, for example, play over a montage of the siblings advancing through stages of their childhoods. Nate Faxon takes over as the teenage Ben. We know he's a teenager because the 37-year-old actor is wearing an ill-fitting Beaver Cleaver cap.
CW's Arrow has constant flashbacks to the years Oliver Queen (Stephen Amell) spent marooned on a desolate island. We know it's a flashback because for these scenes, Amell always puts on a ragged wig that looks like a tippy haystack.
USA's Psych begins most episodes in a time long ago with Shawn (James Roday) getting schooled by his father, Henry (Corbin Bernsen of L.A. Law), on observation techniques. The young Shawn is played by Liam James. The younger Henry is played by . . . Bernsen, with a bad wig and a fuzzy-focus lens.
You want to talk bad wigs? Prime time has given us some recent doozies.
Two toupes on Lost stand out: the one sported by Locke (Terry O'Quinn) as he searched for his father, and the Chia Pet monstrosity Cheech Marin wore as Hurley's dad in his prime.
TV is very fond of this cheapo rejuvenation ruse. I invite you to send in your most cherished examples.
One of my favorites is the hip sideburned variation of Walter Bishop (John Noble) in certain flashback scenes of Fringe. Mostly, I like this ridiculous look because the Mod Squad Noble looks uncannily like Homer Simpson in those scenes when he's a young stud courting Marge.
For sheer silliness, you'd have to go with Danny DeVito in a lustrous Prince Valiant hairpiece in the classic "Frank's Brother" episode of It's Always Sunny in Philadelphia. Really made you miss the disco days.
The most ingenious solution to character regression I can recall occurred on Boston Legal. For an episode in which Denny Crane (William Shatner) was recalling one of his earliest cases, the show spliced in clips from a courtroom episode of Studio One in Hollywood from 1957 featuring a young Shatner.
Every impersonator in the business does Shatner. But nobody does Shatner like Shatner.
Double mitzvah. It was a week of multiple mitzvahs on ABC this week. On consecutive nights, network sitcoms were built around bar mitzvahs.
On Happy Endings, Max (Adam Pally) finds his niche as a "Mitzvah hype," entertaining the adolescents at a series of receptions. He even brings Brad (Damon Wayans Jr.) into the business. Their Dreidl Dance is a sensation.
On Modern Family, Manny (Rico Rodriguez) with the help of Luke (Nolan Gould) crashes a hotel's three simultaneous bar mitzvah receptions to meet the dream girl who smiled at him in the lobby.
Which episode was better? We have to give it to Modern Family because it had a side plot with Phil (Ty Burrell) unwittingly seducing guest star Matthew Broderick over margaritas by the fireplace. You had to be there.
Plot points. Pay really close attention to the next two episodes of Revolution, because NBC's dystopian series is about to be put into hibernation for a very long time. Until the end of March, in fact.
So, focus hard on what's going on so you'll be able to pick the story up again four months from now.
Oh, that's right. Nothing is going on. That's why Revolution is going away in the first place.
Contact David Hiltbrand at 215-854-4552, dhiltbrand@ phillynews.com, or follow on Twitter @daveondemand_tv.