I've already mentioned before that alcohol has little effect on me, much to my chagrin.
Well, the entry on "stoner" reminds me that pot seems to have even less of an effect on me. I've tried mutliple times but I just can't get high.
Then I thought about it, and I don't think caffinne has ever had an effect on me either.
So, maybe I have some sort of drug-immunity superpower.