Although you’ll have heard that Dallas Buyers Club is fantastic and Matthew McConaughey gives the performance of his career, I know you won’t believe it unless you hear it directly from me so here you are: it is fantastic and Matthew McConaughey gives the performance of his career. In fact, it may be the best performance of anyone’s career. It’ll blow your tiny minds. It blew my tiny mind. ‘That blew my tiny mind,’ I even said afterwards, so it has to be true.

Dallas Buyers Club is based on the real story of Ron Woodroof, a difficult hero. Ron, when we first encounter him, is attending a rodeo and having rushed, seedy sex with two women in one of the holding pens. Ron drinks, snorts coke, rides bulls and struts about in a Stetson, with one of those cock-of-the-walk, macho gaits. He is no great respecter of the ladies, and is also profoundly homophobic, as are his unappealing friends. He’s like you always imagined the Marlboro Man would be.

But then an accident at work sends him to hospital where they discover his T-cell blood count is down to nine. It’s 1985, the year Rock Hudson died of Aids, and Ron is infected, through having unprotected sex with a drug-using woman, probably. The doctors give him 30 days to live. He walks out on them, snarling: ‘I’m no faggot.’ He then makes the journey from denial — vigorous denial — to medical activism, taking on the FDA, but this isn’t like other medical activism movies. It isn’t like, say, Erin Brockovich or Lorenzo’s Oil as it never goes all soft and uplifting. Ron never seeks our affection or sympathy, but somehow wins both. This is what gives the film it’s complexity, and depth, and makes it so astounding.

At first, Ron is treated with AZT, which plays fast and loose with his white blood cells, and which even his sympathetic doctor (Jennifer Garner) is beginning to regard sceptically. So he starts importing drugs not yet approved by the FDA, smuggling them in from Mexico dressed as a priest, and selling them on the black market, which he gets done for, so he sets up the club whereby members pay subscriptions for their medicine. He works from a motel room along with Rayon (Jared Leto), a cross-dresser whom he met in hospital, and whom he initially found repellent. The two become friends, leading to a wonderful scene where Ron acts heroically in a grocery store, but the friendship is never clichéd. It feels true, hard-won. Ramon is wise-cracking, but not a comedy character, as Leto also imbues him with heart, and vulnerability, and intelligence, and throws all he has at him, which is considerable. And the same can be said for McConaughey. Only more so.

I’d like to say I spotted McConaughey’s potential in Failure to Launch, and How to Lose a Guy in 10 Days, but I did not. Sorry. But who did foresee he would become such a fascinating actor? You? I think not. First, it was Magic Mike, then Mud, then that electrifying cameo in The Wolf of Wall Street and now this. It’s not just his physical transformation — he lost 40 pounds; by the end, his neck sticks out of his shirt collar like a sad twig — but also his absolute commitment to the character; Ron’s anger; Ron’s urgency; Ron’s fears; Ron’s humaneness; the way Ron snaps that neck round to speak. And all against a fascinating background: the politics of medicine at that time.

Directed by Jean-Marc Vallée, it captures the fear and panic of that generation of gay men who did not understand why they were ill, and why no one was doing anything about it. Still, I was left with some questions. Did Ron actually save any lives, or even extend them significantly? Was the FDA so wrong in banning drugs that had yet to be declared safe? And on other themes: was the Jennifer Garner character — who, I’ve since learned, did not exist, and I rather suspected as much — actually necessary? Or was she merely invented to inject something nice to look at? And, for those who set store by such things, shouldn’t the Dallas Buyers Club have an apostrophe? Yes, I think it should, just as I think you should go see this film, as it will blow your tiny mind, and I feel you can trust me on this, even though I did not spot McConaughey’s potential in The Wedding Planner either. Sorry.