蜡笔曾经不懂小新多啦曾经不懂A梦
[là bĭ céng jīng bù dŏng xiăo xīn duō la céng jīng bù dŏng a mèng]
These references are from popular Japanese cartoon characters - Crayon refers to 'Crayon Shin-chan' and Doraemon was initially known as Dorami before becoming the machine cat 'Doraemon'. The sentence suggests a nostalgic and innocent ignorance of young people who didn't understand or appreciate the stories behind these characters fully.