冷暖不知软硬不吃
[lĕng nuăn bù zhī ruăn yìng bù chī]
The meaning behind this nickname is to describe a person's stubbornness or their unwillingness to yield ('cold or hot water does not make difference to me' and 'I don't care about gentle treatment'), reflecting indifference or a strong personality. It might mean someone isn't affected easily by the attitudes of those around them.