I still find some of the answers weird. It's relatively simple being 18 years explains why you may act like an idiot but it doesn't excuse it because being 18 years old you know what you are supposed to do or not, you also know that there are consequences to your actions because you have been told about them. So when you disregard rules the other adults around you should sanction you and the only thing you should do is shut up and accept the consequences of your actions.
It's obviously not the end of the world and neither should get a life sentence from that event but anyone who is trying to justify or brush it away because they were idiots at 18(I was one myself) seemingly haven't understood their lesson. Harmonious life in society is largely based on order, discipline and respect of others, we need to always keep that in mind. Also if you are treated like an adult, act like a decent one otherwise don't be surprised if no one trusts you and treats you like a child.