Alcohol
Considering the extensive damage alcohol does that we know about now, this quote seems far ahead of its time. A friend who recently celebrated their 5th year of sobriety said that milestone marks the point at which the amount of damage that can be undone is complete. They have to live with whatever brain capacity they have left.
Writers know alcohol invites instability and misery, fodder for more dramatic stories.
Image courtesy of the Canva pro media library.