rookie mistake
noun [ C ] mainly US uk/ˈrʊk.i mɪˌsteɪk/ us/ˈrʊk.i mɪˌsteɪk/ (also rookie error, /ˈrʊk.i ˌer.ər/ /ˈrʊk.i ˌer.ɚ/); (UK also schoolboy error, /ˈskuːl.bɔɪ ˌer.ər/ /ˈskuːl.bɔɪ ˌer.ɚ/)
新手犯的错误，菜鸟级错误
a basic mistake, like one that a person with no experience of an activity would make
Although he's an experienced movie director, he made the rookie mistake of trying to cram too much material into a mere 100 minutes. 他虽然是一位经验丰富的电影导演，却犯了一个菜鸟级的错误，在短短的100分钟里塞进了太多材料。