古人对周公之礼的重视程度可以从多个方面体现出来。首先，古代统治者非常重视人口的增加，甚至有的朝代规定了如果到了年龄还没有结婚，官府会出面为未婚男女介绍对象。这一点可以说明古人对于婚姻和后代的重视程度。

其次，商周时期的人们对于夫妻之间的性行为相对开放。在《诗经·国风·召南》的《野有死麕》等诗篇中，就有关于男女野合的描述，这表明当时的人们对于性行为比较开放。然而，周公通过制定礼法规定了婚前男女不得同房，这也是周公之礼的由来。
然而，到了秦汉时期，人们开始更加注重规矩和礼节，结了婚后也需要遵守一定的规矩。因此，教授夫妻之间的性行为成为当权者的头等大事。东汉建初四年，汉章帝刘炟亲自主持召开了青少年性教育工作会，形成的决议由班固记录并整理编辑成了《白虎通》一书。《白虎通》规定，贵族子弟从10岁到20岁就要离家学习，其中也包括了性教育的内容。

在唐代，李世民甚至亲自给自己的妹夫们上了一堂生理卫生课，将房事要领认真细致地讲解了一遍。宋太宗赵光义与南唐后主李煜的原配发生性行为时，甚至还叫画师当场作画。直到宋代后期，教授夫妻之间的性行为才开始变得隐晦起来。
总的来说，古人对周公之礼非常重视，对于夫妻之间的性行为也有一定的规范和教育。从商周时期的开放到秦汉时期的规矩，再到唐宋时期的开放程度，古人对于夫妻之间的性行为的态度和处理方式有所变化，但都体现了对于这一问题的重视。

----------Introduction in English----------
The importance that ancient people attached to the rites of Duke Zhou can be reflected in multiple aspects. Firstly, ancient rulers attached great importance to population growth, and some dynasties even stipulated that if unmarried men and women were not married at the age, the government would introduce them to them. This can indicate the degree to which ancient people valued marriage and offspring.
Secondly, during the Shang and Zhou dynasties, people were relatively open to sexual behavior between spouses. In the "Book of Songs, Guofeng, Zhaonan" and other poems, there are descriptions of sexual intercourse between men and women, indicating that people at that time were more open to sexual behavior. However, Duke Zhou stipulated through the enactment of etiquette laws that men and women were not allowed to have sexual intercourse before marriage, which is also the origin of Duke Zhou's etiquette.
However, during the Qin and Han dynasties, people began to pay more attention to rules and etiquette, and after getting married, they also had to abide by certain rules. Therefore, teaching sexual behavior between spouses has become a top priority for those in power. In the first four years of the Eastern Han Dynasty, Liu Xuan, the Emperor Zhang of Han of the Han Dynasty, personally presided over a youth sex education work meeting, and the resolutions formed were recorded and edited by Ban Gu into a book called Bai Hu Tong. Bai Hu Tong stipulates that noble children should leave home to study from the age of 10 to 20, which also includes sex education. In the Tang Dynasty, Li Shimin even personally gave his brother-in-law a physiological and health class, explaining the essentials of sexual intercourse carefully and meticulously. When Zhao Guangyi, Emperor Taizong of Song Dynasty, had sexual intercourse with the original partner of Li Yu, the queen of the Southern Tang Dynasty, he even had painters paint on the spot. It wasn't until the late Song Dynasty that teaching sexual behavior between couples began to become obscure.
Overall, the ancients attached great importance to the ritual of Duke Zhou and also established certain norms and education for sexual behavior between spouses. From the openness of the Shang and Zhou dynasties to the rules of the Qin and Han dynasties, and to the degree of openness during the Tang and Song dynasties, ancient people's attitudes and ways of dealing with sexual behavior between spouses have changed, but all of them reflect the importance attached to this issue.