Sacred Haven of Debauchery

people are forbidden from dying after the age of 18.

Once upon a time, the law officially prohibited this.
Now, it has remained at the level of strong public condemnation ("Have you thought about your parents?! How would they feel?!"), and, of course, the good old religion never fails ("Our all-forgiving God will send you to hell for daring to dispose of your own life").
And in our country, for example, it is forbidden to help such people, even by simply providing them with useful information about methods of dying.
In short, formally, the law does not prohibit it, of course, but we all understand.