Not all drugs are legal in Portugal and you can only have consumable amounts like 1 gram of hash/weed.
You're allowed 5 grams of cannabis, which is plenty. It's not just the 'Drugs freely available for everyone!' idea that I like, it's the treating of addicts as patients, rather than criminals, and giving them help and support, instead of locking them up somewhere where it's easier to get smack than it is outside.