When I was 17 I had a bad cough and my mom gave me what turned out to be too much codeine cough syrup. An hour later I realized my cough was gone but I had spent all that time staring at my Windows ME desktop, in some sort of euphoric daze, repeatedly selecting and deselecting all the icons. For an hour! It was really, really creepy and deeply unsettling. And this was codeine, a "mild" opiate! Have aggressively stayed away from opioids ever since then.