Themes
We all are born mad. Some remain so.
— Samuel Beckett · Waiting for Godot

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker proposes that everyone begins life mad, then adds that some stay that way. The short second sentence supplies a dry sting, turning an apparently universal condition into a distinction among adults. Irrationality becomes a shared beginning that people supposedly leave behind to differing degrees.
Context reviewed