难过就告诉自己我是混蛋
[nán guò jiù gào sù zì jĭ wŏ shì hùn dàn]
In English this translates to 'When sad, tell myself I'm an ass.' It suggests the way the person uses self-criticism or even self-degradation to process feelings like regret and guilt, or sometimes this can just be used for humorous self-mockery, reflecting on foolishness from the past.