Fresh air is good if you do not take too much of it; most of the achievements and pleasures of life are in bad air.

Summary

This quote suggests that while fresh air is beneficial, it should be enjoyed in moderation. It implies that too much comfort and ease can lead to complacency and prevent one from experiencing the challenges and growth opportunities that come with difficult circumstances. It emphasizes that many of the meaningful accomplishments and joys in life come from enduring and surmounting obstacles, rather than passively seeking comfort and avoiding difficult situations.