Why do we feel sorry for people who can't travel? Because, unable to expand externally, they are not able to expand internally either, they can't multiply and so they are deprived of the possibility of undertaking expansive excursions in themselves and discovering who and what else they could have become.
In youth, we live as if we were immortal, knowledge of mortality dances around us like a brittle paper ribbon, that barely touches our skin. When in life does that change? when does the ribbon tighten until finally, it strangles us?