The tea ceremony is not a "ceremony" in the sense of, say, a wedding ceremony or a graduation ceremony.  One one level, it is nothing more than following a set of predetermined actions--spoken phrases and unspoken gestures--designed to create the most harmonious, elegent, and yet efficient means of serving tea to guests.  In the most basic form of chanoyu, called usucha ("thin tea"), the guest enters a simple tatami-mat room; the host enters, greets the guest, serves kashi (candy),  brings in the necessary implements, cleans them in front of the guest, mixes and serves the tea, then cleans the implements again and removes them, then leaves, allowing the guest to leave.  In some ways, this is similar to inviting someone to your house for tea and cookies.  In three ways, however, it is very much different:  the host does all the "work" in front of the guest, the host and guest communicate through unspoken gestures rather than a lot of talk, and the guest must bring his/her own "napkins and silverware."

So why does something so simple take a lifetime to study?  There are essentially three reasons:

1) The tea ceremony is not done just one way.  Portions of it change with different seasons of the year, times of the day, numbers and class of guests, levels of formality, shapes of implements, and size of the tearoom.  In addition, a chaji, or complete tea ceremony, includes fixing in front of the guests the charcoal underneath the boiling water, serving a complete light meal called a kaiseki, and the serving of a more formal koicha ("thick tea") prior to the usucha.

2) As the above implies, performing tea ceremony requires an understand of a number of areas of Japanese culture.  One must learn how to prepare the meal, design and maintain the tea room and the outside garden, discern the different styles of ceramics, metal-, wood- and bamboo work available in Japan and elsewhere, discern calligraphy and design simple flower arrangements for display, plus a knowledge of textiles for the Japanese kimono and implement covers.  One could argue that the most effective means of learning practically all the aspects of traditional Japanese culture would be to study chanoyu.

3) Learning all of the above would make one into an effective chanoyu robot, but would do nothing to prepare one for the deeper aspects of tea.  Chanoyu is not a religion, and the tea ceremony is not a religious ritual; those who practice tea include Buddhists, Christians and many others.  The discipline of studying chanoyu, however, is also the discipline of learning about oneself, and how to relate to others.  The "motto" of the tea ceremony is wa-kei-sei-jaku, or harmony, respect, purity and tranquility.  To the untrained, the idea of spending anywhere from 15 minutes to 3 hours sitting on one's ankles, making and drinking two-tablespoon servings of a bittersweet bright green drink, may sound preposterous.  The essence of the tea ceremony, however, is not found in the tea, but in the tranquility that comes from learning how to harmonize with others, respect others and oneself, and gain purity in thought and action.  To the Buddhist, the empty tearoom is like the mushin (literally "not-mind") of Zen; to the Christian, the candy and tea are like the bread and wine of Christ's communion; but to all people, the world apart from the stress and battle of the "real world" that is found in chanoyu points the person of tea to the things in life that last far beyond the concerns of the material--and that is a lesson that is more than enough for any lifetime.