'Don't get uptight with me, man. Cos if you do, I'll have to give you a dose of medicine. And if I spike you, you'll know you've been spoken to.'
Withnail: 'You wouldn't spike me, you're too mean. Besides, there's nothing invented I couldn't take.'
Danny: 'If I medicined you, you'd think a brain tumour was a birthday present.'
As fond as I am of Withnail and I, you'll just have to take my word for it that I don't have much personal experience of illegal drugs. I was passed a spliff once at university, took a draw and felt so sick that I haven't bothered since. A wit once remarked that there was little point in me wasting my money on cocaine, as I already demonstrated the outward behaviour of someone who sprinkled the devil's dandruff on his cornflakes.
The only reasons I'd favour legalisation of drugs, even Class As, are to get the crime rate down and the tax take up. I fully accept it's both unfair and illogical that a student can go to Lidl and get a bottle of vodka that he necks before heading out for an evening of fun, nutting all and sundry, wasting police time and nuking his liver, before finally spewing all over an A&E nurse at 2.30am while the mild-mannered stoner commits an offence by sitting quietly at home watching Countdown with his Camberwell carrot. The booze bootleggers got respectable and legal before the stoners.
Things will change, as they have begun to in the United States with decriminalisation on the march. A staggering 40% of those imprisoned worldwide are inside for drugs offences and the US has 25% of global prisoners.
There's a big generational thing going on here that will lead to further change. It's not just gays with whom Nigel Farage and his fans feel uneasy. If the UKIP fuhrer posed with a legal high rather than a pint, it would be the end of him.
But would legalisation mean we'd all get swamped by a tide of pills and weed? One hopes not. Surely the problem really is that we need fewer mind and health-damaging drugs around the place not more.
Follow Matthew on Twitter @MatthewGwyther