To have seen much of life and have wide experience; to be sophisticated and knowledgeable about how the world works.

to broaden one's horizons or gain experience through exposure to society

To have little knowledge of the world; to be inexperienced or unsophisticated.

To be green and inexperienced; to lack experience of the wider world.

Metaphor for steeling oneself through practical experience and hardship to gain wisdom and broaden one's horizons; to mature through real-world challenges.