Science

Fun fact: it actually takes a while to get addicted to opium

You also have to have some kind of special receptor to get euphoria from it, which I lack.

You should probably stop spreading misinformation. No drugs cause immediate physical dependence but every dose changes your body and causes reenforcement learning. It doesn't really make sense to try and find the dose that gets you addicted, it it when you get crippling withdrawls? Or you know all the doses that lead up to that.

Opium is a crude extract (the latex of papaver somniferum, aka breadseed poppy) containing many alkaloids but the primary one that causes pleasure is morphine. Morphine interacts with the mu opiod receptor, activating it. It's possible you might lack it but I am not sure you would work properly, it's very fundamental and regulates so many low level processes (hence why you can stop breathing or get lethally constipated). If you lack it, almost nobody else does.