Culture is the thing embody everywhere. Your behavior, altitude and character reflect the culture all the time. It is ubiquitous from the basic etiquette to the literature. Unable to see or touch but we can clearly feel it exist. We may fail to say something is the culture, but we always say something embody the culture. I basically agree with the speaker that in order to truly understand your own culture, you should at least requires the knowledge of at least one other culture. One that is distinctly different from your own.
Without a comparison, people can definetly realize their culture, but can hardly reach the level of truly understant. We cannot deny throught the traiditonal festival, etiquette and literature we can have a consciousess that such thing reflect our culture. However such thing is only restricted to a dim level unable to point out the denfinit content. Comparison help people point out the differences and similarities, designating the content of culture let people realise the triffle in our normal daily life may be the result of the culture affect. We may fail to point out that the secretive and reserved which are the two characters widely accepted by Chinese respresent the culture from the foreign people. We may unabel to tell that the chopstick we use everyday, the yellow cap which every primary students have to wear and radio gymnastic exercise, all the staff embody the differential culture.
On the other hand, we should also have a clear awareness that what the speaker mean "truly understand" is not base on the degree of realization, it should ascend in a higher lever. In that case, the comparision can simply resolve the recognition problem telling people what is the culture may contain, where can we find it, whereas lack of the denfinite information about the originailty of the culture. The appearence of the culture may confused people making them trap in a labyrith. To entangle the diverstiy fact, people need to have a deep study of the national culture longitudinally. Starring from the hisrory seeking the reason causing the present phenomenon, following the development should we have a clear thought of the meaning of culture. If we only see the character different between the westn and easten culture, which the open and personality may better ilucidate their culture, we cannot realise that the thing root in western people's character stem from the reconition of  competence, eastern country from the other point originate their highly value of the harmony.
From this point, in order to reach the understand level, the selfstudy is indispensible. At the same time the realisation of the nearby culture may strenghten our understanding of it. For instance, Although the Budiism is stem from the India, the Buddhism culture in China has a large different to the india. In India the benefection of food to monk is seen as cultivating virtue, hence the monk do not need to worry about the food, on the contrary, in china every monestery live a self-sufficiency life which cultivate the commertial developement, monk have to consider the way to maintain the monestery be wildely worship for the money thry need to live.
In the final conclusion. the speaker may only put attantion on the outset realization of one own culture which the comparison consitude the majority part. Insteadly, to truly understand one culture, the comparsion is far enough. The deep study of culture through various of information may be seen as a vital way to hit the target.