"How can I forget who you are?" According to Kugou Music, "Youth is so beautiful" is a lyric from "How Can I Forget Who You Are" written by Yu Zhuo'er, composed by Chen Wei, and sung by Uncle Qiuku and Chen Rui. This is the first line of the song, and the next line is "Thoughts are so precious, but it's a pity that time passes like water and never comes back."