The Fact that Dumb and Dumber To doesn't strike you as the best movie of the year is because the original has an outsized reputation simply because we remember it – that wasn't a great film either.

The pleasant surprise is that neither Jim Carrey or Jeff Daniels as Lloyd and Harry have lost the comic chemistry that made the first one enjoyable, nor have the Farrelly brothers lost the essential essence of the pitch – that these two guys are irredeemably dumb.

It sounds like an easy thing to do, but upon closer inspection, having the audience like and root for two stupid guys who essentially don't change is a balancing act the movie succeeds at.

The movie exists on the merest of narrative whims. As you've seen from the trailer, nothing's happened for Lloyd or Harry because Lloyd's spent the last 20 years pretending to be catatonic, living in a sanitarium and having Harry tend him every day, all for a prank.

After he comes clean (and Harry loves the gag as much as Lloyd does), they return home to further adventures, meeting the now grown up blind kid bird lover and preparing to go on with their lives.

But when it turns out Harry has a daughter from an affair from years before and Lloyd falls in love with the picture of her, the guys set off to track the girl down.

Kathleen Turner is so unrecognisable as Harry's former fling I didn't even realise it was her for about five minutes, but she gives the guys the lead they need and they set off to find the rich family Penny (Rachel Melvin) now lives with and who coddle her mercilessly because of how much like her biological father – ie stupid – she is.

But her stepmother (Laurie Holden, of The Walking Dead) is scheming to do away with Penny's rich, eternally patient father, and when Harry and Lloyd visit the family right after Penny's left town to attend a big conference, they're dragged into the diabolical plan – and of course have no idea what's going on.

A few weeks after watching it you'll be hard pressed to remember anything particular, but while you're in it you'll laugh as much as you did the first time.