I believe you. I don't think the buzz would happen consistently if you tried to replicate it over and over. It could have been your anxiety going away, or it could have been the placebo effect.

One could easily resolve the question of whether opioids cause euphoria by doing a double-blind clinical study. I would love to do that study, in fact.

Actually, I remembered that there are relevant results from clinical studies that are available. Here are the side effects of OxyContin.[1] (Euphoria is considered a side effect.) The most commonly-reported side effects were constipation, nausea, and somnolence. If you look down further, you can see that both euphoria and dysphoria were reported rarely.

[1] http://www.rxlist.com/oxycontin-drug/side-effects-interactio...

They already do these studies to test opiates vs other painkillers. Opiates kick ass.

Or maybe you're right: they just take away pain. But it turns out a lot of us have existential pain so it works all the time.

The worse you feel, the more you will enjoy opiates.