I think that the aspect of archaeology that interests me the most is knowing how culture, art and symbols for communication can change stylistically over time, yet show patterns. It seems to me that there are phases of culture that show up over time, phases that develop and have horizons as cultures develop. The phases of "Pre-Classic", "Classic", and "Post Classic" that can be seen in pre-Columbian archaeology of Central America personally gave me insight into many other cultures seem to change and evolve over time. What I find interesting is how the shape of pottery and symbols for a certain time and region will be different from another piece of pottery from the same region and culture at a different time due to cultural shifts is style. This shift in cultural style is easier to see through the science of linguistics, where the meanings of words can shift radically over a generation or even a decade. Words can come to mean the opposite of what it had meant only a few decades earlier. A similar sort of shift in style can be seen in types of pottery from ancient cultures where shapes and symbols are repeated over and over, yet change over time so that while the meaning is static for a symbol the shape changes over time. Yet,any major cultural shift in style that might be found in the archaeology Central America from say "Pre-Classic" to "Classic" might represent many smaller shifts in cultural symbols. It might be obvious that cultural shifts often follow major political or social changes. When we look at how cultures evolve from simple or crude beginnings into major empires, the idea of a linear series of phases of cultural changes makes sense.
So, what I find interesting about archaeology is not only studying artifact styles and being able to know where they belong within a sequence of cultural shifts, but in understanding that cultures can and will change, altering their symbols and styles over time. The reasons for, or forces behind, these shifts may not be known however, the fact that cultures change this way is irrefutable.