Gareth O'Callaghan: I consider myself fortunate that cannabis didn't 'agree' with me

A psychotic episode in my youth served as a lifelong warning to me — others weren't so lucky

'I recall taking three long inhalations from the joint. Its effects were not what I’d expected. Within seconds, I was living inside an unfamiliar space in my mind that was on the verge of freaking out.' Picture: Getty

They say your sense of smell is like a portal to forgotten memories. I was sheltering from heavy rain last weekend in the doorway of a busy shop when I got a familiar smell hanging in the air — earthy, woody, with a tinge of citrus, almost skunkish.

I realised the guy standing beside me was smoking cannabis, taking long drags from the joint and blowing the smoke out into other people’s faces. So if he was smoking weed, then inadvertently so was everyone else standing in the doorway. To avoid it, I either had to step back out into the torrential rain, or stand there and inhale.