If you want diversion while enduring the Farrelly brothers' largely terrible, depressingly tardy – though amusingly titled – sequel to Dumb and Dumber, then ponder what the exercise says about movie celebrity.

Twenty years ago, Jeff Daniels was a respected, modestly famous character actor who brought a bit of weight to his partnership with energetic, newly unavoidable sensation Jim Carrey. In 2014, Jeff Daniels is a respected, modestly famous character actor who brings a degree of weight to his partnership with sagging, newly underperforming has-been Jim Carrey. If you shoot that bit higher then you have that bit harder to fall.

The imbalance invests Carrey's performance with an extra degree of desperation. The Canadian has never held back in his efforts to bludgeon audiences into submission, but, in Dumb and Dumber To, he seems constantly on the point of falling to his knees and begging us to laugh.

Few will comply. Times have moved on and what once seemed simultaneously fresh and disgusting now feels depressingly threadbare. We begin with the decent joke you have seen in the trailer. Harry (Daniels) visits Lloyd (Carrey) in a care home where, for the last 20 years, he has apparently been rendered catatonic with unfulfilled love for Mary “Samsonite”.

It transpires that Lloyd has been playing a prank and, after chortling revelations, the two once again find themselves on the road.In truth, the script is not significantly weaker than that for the first film. Daniels and Carrey resume their partnership as if little time has passed. But one can’t escape the sense that these gags needed novelty to thrive.

Perhaps the best comparison is with The Sex Pistols. Dumb and Dumber, still funny after all the convulsions, reminds us of the young punks bellowing Pretty Vacant at the 100 Club. Dumb and Dumber To suggests the butter-flogging Lydon playing to middle-aged festival-goers in luxury yurts. It's already made plenty of filthy lucre in the US.