I kinda disagree, she was driving baked. Smoke enough weed and being baked is like your second sober, or even your normal. I mean I can't even remember the last time I smoked weed and was like "dude, I'm really fucked up" Maybe when I was 14?
If one smokes frequently or generally does some kind of drug on a frequent basis, even maybe overlapping one another, then it will change your general level of attention. The reason you don't get fucked up is you still have enough of an amount in your blood from your last session that the brain doesn't recognize it as a severe increase. You don't feel fucked up, because you've been constantly semi-high for however long you've smoked frequently.
And if you smoke only on occasion I can't understand how you don't get fucked up. I do if I quit for like a week, and I've been a steady smoker for six years lol.
Anyway, it is statistically, medically and practically shown that while under the influence of THC, your reaction time is reduced. Driving in traffic is dangerous enough as it is, that small margin might contribute to an accident. In other words, an unnecessary risk.
If nothing else, it's fucking retarded to drive around stoned cause if you get caught they'll take whatever you have on you, your license, and you'll be fined. If you HAVE to be at someone else's place to get high, take the bus or a cab, or walk. Or sleep over. Or if getting high is so important to you, have friends come over. If they won't maybe you quit the shit for a while and get a life and some friends that will come over (read: my life).
none of this directed at Da_Funk, just in relevance to what he said and "you" refers to anyone that feel hit