Did you know that not only does marijuana kill you; it kills everyone around you in a 5 mile radius, their families, and anyone that their families have had sexual contact with as well.
Truly frightening stuff.
Marijuana also not only extinguishes your sex drive entirely, it retroactively cancels all sex that you and anyone you come into contact with has ever had. This can sometimes blink children out of existence and create Back to the Future-esque paradoxes.
In fact that's how they got Michael J. Fox's hand to disappear during the dance scene. They smoked just enough to fade him to the elbow, but luckily they did not inhale.
Also marijuana will commonly encourage you to drive over state lines just to inadvertently hit your grandmother with your car.
The ancient Mayans used to use marijuana for travel. They would send out their grandmothers, tied to a donkey's back. The donkey would take them to a desired location (This is known as "Establishing a Grandmother Beacon"). Then all they had to do was smoke a bit and they would summon a used 1990's Honda Civic, whose bumper would automatically seek out their grandmother like a homing missile.
It's a powerful drug.