怪我太年轻是人是狗看不清
[guài wŏ tài nián qīng shì rén shì gŏu kàn bù qīng]
This username humorously expresses the regret of being too naive or inexperienced in life. It literally means: 'Blame my young self for not being able to distinguish people from dogs', implying difficulty in judging good people from bad.