精神病就是任性
[jīng shén bìng jiù shì rèn xìng]
It's a colloquial expression that translates to 'Mental Illness is just Recklessness' or 'A crazy mind does what it wants.' It shows a nonchalant or rebellious attitude, as if mental illnesses give an excuse for unpredictable behavior, though this might be seen as trivializing real mental health issues.