What did Socrates mean when he said: "the unexamined life is not worth living"?

Freedom comes from self-awareness.

If you are aware, but not self-aware, your actions are compulsive responses to circumstances.

If you are self-aware, they are reasoned and deliberate responses.

The unexamined life is the life devoid of self-awareness and, therefore, devoid of agency.

And that is what Socrates meant.