A couple of years ago, Magic Trip, the artful reassemblage of the 16mm footage shot on Ken Kesey's 1964 "Merry Pranksters" bus trip, gave us rare moving footage of Neal Cassady. And, watching this well-meaning but laboured and disjointed adaptation of the 1951 Jack Kerouac novel that came to be seen as defining the Beat Generation, I couldn't get those images of him out of my head.
At the wheel of the Pranksters' bus, Cassady was a frenzy of drug-fuelled energy. Equal parts Fritz the Cat and Aladdin's genie, he was wired enough to power a small city and you had to marvel at the fact that they made it to the Nevada border, never mind New York.
It's hard to find that man in Hedlund's incarnation of him (or rather his fictional analogue, Dean Moriarty; Kerouac's publisher insisted all his characters have new names). He's certainly a laid-back sybarite whose appetites for both drugs and sex are so voracious and catholic they seem almost post-modern in this anxious age: watching him smash Benzedrine Nasal inhalers to make instant-hit tea out of the contents will leave the unhorrified in awe of his inventiveness.
But he's altogether too smooth and self-regarding to be the Moriarty Kerouac gave us, more bedraggled peacock than scrappy seagull.
A film adaptation of On The Road has been a long time coming. Kerouac himself tried and failed to get Brando interested in the 1950s and Francis Coppola has tried several times to get projects to fly since he acquired the rights in 1979. (Mercifully the one that had Brad Pitt as Moriarty never got off the ground.)