What do you mean by studying hard for a thousand years and smiling at a thousand poems?

"Studying the Millennium history and laughing at the Millennium poems" means studying the Millennium history books, appreciating and reciting the Millennium poems, and describing them as hard-working and knowledgeable. This sentence comes from "Yan Zhenqing Regular Script Collection Couplets, Textual Research". Yan Zhenqing is a famous calligrapher in the Tang Dynasty, and his calligraphy works have high artistic value.