It's official: heavy cannabis use as a teenager makes us stupider adults, knocking an average of eight points off your IQ.
For today's grown-ups, those are the missing points fooling you into remembering Cypress Hill's whiny stoner dirge as 'really excellent music' (it doesn't, it sounds like a man with sinusitis reading sections of the phonebook), or believe Up In Smoke by Cheech and Chong is a comedy classic.
If you spent the 1990s doctoring WD-40 cans, your parent's best cutlery set, fish tanks, demi-johns and buckets in a bid to ensure your personal weed level never fell below really bloody mangled, there's a chance your A-Level revision for French verb endings fell somewhere short of slapdash.
We're talking heavy cannabis usage here. Not the majority of 30 somethings who had a few honks on a clumsy three-skinner around the back of a school disco, felt a bit wonky and spent a surreal journey home in their mother's Volvo listening to her Daniel O'Donnell CD through a freshly blown mind. You guys are okay. Don't hand yourself in at A-amp;E just yet.
Continual large amounts of cannabis, however, makes people quite boring, curiously tired, underachieving and cosy in the eco-climate of their less than lemon-fresh underwear.
It's one of the worst drugs. At least MDMA tempts one to leave the house and enter clubs or dark raves, chat to strangers and imagine oneself, temporarily, as a heavenly creature lighting up dancefloors.
Heavy cannabis users just trudge on and on in one long, spliffy groundhog day.
Men: try adding "I smoke a lot of weed" to your internet dating profile and enjoy your long, stoned walk in the sexual Gobi desert. 'Freeing the weed' is not one of my political views. Obviously, trendy liberal types like me aren't supposed to say this as this would be 'getting tough on drugs', which I have no plans to do. Massive weed-smokers don't need our anger - they need our gentle and merciless derision.
I suggest you start by typing the words 'Puff Puff Give' by HannaH's Field into YouTube and savour the toke-tastic twaddle of a pro-weed smoker bashing away on bongos, proclaiming that weed "comes from the earth, the earth can't hurt". (HannaH was stoned the day her school was teaching her about Deadly Nightcap mushrooms and the contamination at Sellafield.)
Dear God, I saw the greatest minds of my generation fail their A-Levels and then sit in a ropey tattoo parlour having a green cannabis leaf inked onto a forearm with 'Legalise cannabis' beneath.
"What do you think?" my ex-boyfriend asked, slumped on the shop's back step, haphazardly erecting a single skinner of Red Lebanese lest he gain a clear mind for one minute and realise he'd neither sent off his Ucas form nor changed his Kappa hoodie top - a Jackson Pollock of curry-sauce flecks, hot-rock holes and WD-40 stains - in weeks.
"It looks like a crap shamrock," I said. I split up with him soon after and it took him eight weeks to work it out, as Super Mario All-Stars had just come out.
I'm certain he lost part of his IQ along the way and missed out on student debts and pressure. And he also lost me as a girlfriend.
Some people will say things worked out quite nicely for him.