The significance of eating has changed as knowledge about food accumulated. While in primeval times eating meant only to fulfill human's stomach and regain energy with edible things, it refers to  branches of scientific study ( nutriology, food safety testing, etc. ), a sort of economy ( hog futures for example), and even represents a kind of culture now. Things seem to be more complex and profound as people learning more about them, but they never become more mysterious. That due to our gradually developing , thorough comprehension into the cases can human civilization living on.     Learning what existing is far more efficient and effective than find it out by oneself. It is almost impossible for an individual to witness the whole processes of something as much of substance in nature growing more sluggish than human bodies, the rising and wilting of a political party as a case in point. Acquiring knowledge is necessary for handling measures and methods in order to study things comprehensively and penetratingly, and to solve problems. For instance, an average school child comparing discounts between two candy stores can calculate more accurately and faster, use and control fire better to heat a bottle of water, than a prehistorical adult.
    Apprehension on a case is much more detailed and complicated as stock of knowledge thickening, although the case may remain unchanged, which makes the case seemingly more mystical. Galaxy means massive substances in the universe according to oceans of astronomical evidences, but this common sense was considered as mad and ridiculous among medieval scholars whose ideology was circumscribed by their plain thoughts on stars and planets. Moreover, things are developing along with the evolution of human society. Colleges of medicine and hospital provides a case in this view, that in the very beginning, there was no such branches as neuroscience, gynaecology and otorhinolaryngology. However, the areas medicine covers are broadening rapidly, technologies as complex and difficult as CPR, organism replantation and baby Test-Tubed are ordinarily practicable.
    Further more, comprehensible and complexity are not mutually exclusive. The position one take determines the view from his eyes. One carambola may show a oval outline, yet its shape also appear like a star from a certain aspect. The complexity of studying things might just contribute to the simplification of knowing them. Mouses, which facilitate the controlling of personal computers for the public, emerged only when the technologies of computers were well-developed enough, nonetheless, its emergence simplifies the manipulation in that people do not need to recite lots of complicated orders using the keyboard.
    It becomes more difficult to know in all fields as the exploding of knowledge and information. People tend to know more, but they simultaneously find out that individuals are too feeble when confronting with the flood of knowledges, according to which some may argue that things are becoming more mysterious and complex as we recognizing more figures of them.    Yet it is too hasty to conclude that there is no good to deepen our knowledge and to acquire more information: catching just a cold might triggering a decimal killing in the Middle Ages, however, with the developing of medicine science, both human health and human longevity are enhanced. Whether a set of knowledge is useful or not is not depicted by its complication, but by its practical utility and developing potential.