孤独成性不过是看透人心百毒不侵不过是看清人性
[gū dú chéng xìng bù guò shì kàn tòu rén xīn băi dú bù qīn bù guò shì kàn qīng rén xìng]
This reflects a cynicism towards social life. Loneliness becoming a habit merely shows one has seen through others' intentions; being unmoved and resistant ('immune to poisons') comes from fully understanding the nature of people, implying world-weariness and isolation.