现实给了我一耳光指着旧伤不准我忘
[xiàn shí jĭ le wŏ yī ĕr guāng zhĭ zhe jiù shāng bù zhŭn wŏ wàng]
It's a metaphorical statement expressing how reality (or difficulties encountered) has harshly reminded the user of past painful experiences and doesn't allow them to forget these wounds. This highlights struggles and challenges faced, and possibly the pain of unhealed old wounds.