So, here's how it goes:
The toxins found in plants serve to deter animals from eating them. Over time, humans are supposed to have evolved their own characteristic to counter these effects. But, it goes more than just immunity, yes, I'm talking about drugs. Those same toxins act on the reward centres of the brain to give that high.
My first impression was, wouldn't it have evolved out, considering that drug use leads to, shall we say, evolutionary disadvantages (death, serious damage, whatever)? And why make it "appealing" rather than just providing a defense against the toxins' effects?
But then, thinking about it more, I compared it to an oyster. An oyster could easily have evolved with an enzyme to break down the annoying grit, I mean, it's just as plausible and probably makes more sense than coating it with mother-of-pearl until it turns into that semi-precious orb, right? By creating pearls, oysters are harvested. Wouldn't that be a bad thing, evolution speaking, compared to the alternatives?
But, if an oyster started secreting an enzyme to break down the grit instead, it would still be harvested, because the people catching them wouldn't know that this oyster was "special" and the trait wouldn't have a chance to be passed on. Thus, the trait doesn't have a big enough impact on the oyster population to make a difference.
In the same way, while it's certainly queer that humans would have this way of counteracting neurotoxins from plants, the simple fact is that deaths and damage from doing drugs doesn't have a big enough effect on population sizes to make a difference, considering that people die in greater numbers from everything else collectively. We haven't evolved a special-shaped skull in order to diminish the shock caused by an anvil falling on it, or several extra appendages, though most people wish at some time in their lives that they had them.
The effects of several of these drugs have also been used for medicinal purposes, and no, I'm not talking about marijuana. So, while it seems strange, it makes sense, in an odd, twisted, high oyster sort of way.

Allo....I'm not my usual verbose self, but I thought I should at least post something...
My life has been pretty boring. I guess it's one of those "go through the motions" things, something that you don't have to do, but should, because otherwise you never will do anything, but can't think of anything worth doing it for.

So here's my situation. I will try to make it as simple as possible.

I like guy A. He doesn't know I exist. Okay, so that's a common enough problem. It gets worse. I used to like guy B. He was one of my best friends, but he started dating one of my other best friends. When they broke up, there was this huge mess that almost ended up with me refusing to speak to my friend ever again. Guy B left our little group of friends and I haven't talked to him since. I want to, but I can't. I still like him, but I want to be over him, because I like guy A. I don't think I am over him yet, but it's been a year and we don't even talk anymore. I keep saying I just miss him as one of my friends, but I can't help thinking that it's not true. And then my friend, the same one who used to date guy B, hates guy A and doesn't want me to like him. She told one of my other friends, we'll name him guy C, that if he asked me to our dance I would say yes, which is true because he's my friend, but I'm afraid he'll start thinking I like him, which is not true and I would hate to be put in the situation of saying so. So he asked me, and I said yes, but I'm still afraid of that! So it's basically between 3, one of whom doesn't know I exist, one of whom I haven't spoken to in a year, and one of whom I don't actually like. What the bloody hell is going on, that's what I want to know. I don't know my problem exactly, just that there is one and it needs to fixed, and I don't know how. Help, O bloggers, I entreat you.......