你以为我无坚不摧我以为你百毒不侵
[nĭ yĭ wéi wŏ wú jiān bù cuī wŏ yĭ wéi nĭ băi dú bù qīn]
You Think I'm Indestructible; I Assume You're Impervious: It implies that there's mutual misapprehension between two people, where each underestimates the vulnerabilities of the other. There's a feeling that one has been toughened up by life and believes the other also possesses great resilience, hinting at misunderstandings in a relationship.