悲喜一瞬间此悲伤非彼悲伤
[bēi xĭ yī shùn jiān cĭ bēi shāng fēi bĭ bēi shāng]
The net name suggests that feelings of joy and sorrow can be experienced abruptly and intensely; the 'sadness' here reflects not just a simple sorrow but a specific emotional turmoil which cannot be equated with other forms of sadness.