The TV spin-off can feel like an open goal for producers looking for their next big hit. Yet for every Frasier and Better Call Saul, there are a few dozen Joey and Cleveland Show types threatening to desecrate the loving memory audiences own for the original source. While both Joey Tribbiani and Cleveland Brown were arguably odd choices as the chosen ones given another life away from Friends and Family Guy, there was never any doubt that should an alternative universe emerge from The Big Bang Theory, it would have to revolve around Sheldon Cooper.

And lo, here it arrives in prequel form as we trace the school years of a Texan kid who wore a bow-tie and adopted a Midwestern accent to separate himself from the hicks he finds himself surrounded by (in the main this means older brother George, who for his part is aghast that his prodigious younger sibling is being parachuted ahead into his own grade).

The voiceover from older Sheldon Jim Parsons gives it a Wonder Years vibe, but the show really belongs to young Sheldon. Seen last year as Shailene Woodley's misunderstood cropped-hair kid in Big Little Lies, Iain Armitage is a revelation as the future theoretical physicist. Not only has he meticulously studied and replicated Parsons' vocal ticks, he portrays Sheldon's lack of social filter with glee, thinking nothing of exposing the flaws of authority figures from teachers to pastors.

Naturally, this being a modern US sitcom, there are moments of sentimentalism that will have you either snivelling or vomiting. So, if you think you'll feel the latter bubbling up when hearing that the stridently atheist Sheldon accompanies his mother to church because while he might not believe in god, he firmly believes in 'mom', then consider this a warning. But for those who can handle a smattering of schmaltz with their diet of sitcom, the laugh count should more than compensate.

Episodes watched: 1–4 of 13.

Young Sheldon starts on E4, Thu 22 Feb, 8.30pm.