The Jewish Journal has an amazing profile of Professor Raphael Mechoulam, 80, who teaches at Hebrew University in Jerusalem, and who 50 years ago discovered THC—the active (so to speak) ingredient in marijuana. You should read the whole thing, but it is worth highlighting his narration of the only time he ever sampled the stuff:
My wife baked a cake and my research partner and I spread THC (tetrahydrocannabinol, the oily, active ingredient in cannabis) on the top. We used 10 mg of THC on each slice—too much, I think—and we and a group of friends and colleagues started eating.
I felt a little high, but nothing more. My wife said she didn’t feel anything at all. One man said he didn’t feel anything, but started having laughing fits for the next hour. One woman had a bad trip—she was a very reserved person and suddenly she felt exposed in front of everyone. One man said he didn’t feel anything, but then didn’t stop talking for three hours, which I suppose was to be expected since he was a member of Knesset.