My thought process:
1. The qur'an does not explicitly mention weed.
2. Weed does not "intoxicate" in the same manner as alcohol. (Or so I am told.) While one dulls the sense, the other makes you feel at peace and makes you ponder. about thing like the colour of the wall and maybe more.
3. In the current age of science, we know that most substances have an effect on the brain. All food, sugar, drinks, tea/coffee and other things containing substances such as caffiene.
So, I weed REALLY haraam?