The Netherlands has a bit of a reputation as a party country, where the use of alcohol and drugs is normal. That image is not quite right. Yes the use of 'soft' drugs (marijuana) is tolerated, but not in public. And a drink after work is nice, but you don't have to go wild, and not every day either.
If you want to know more about these habits, what is and what is not acceptable, read the document below. If you think you have a problem and you want to reduce or stop, check out the relevant links, they can certainly help you!