The Timelessness of "Cool"

    Slang is an inherent part of every language and region that we all inevitably use. Periodically, however, the same terms of slang we use to refer to something are replaced to refer to the same thing in accordance with political or social movements, cultural phenomena, or even due to spontaneous, untraceable reasons. Whatever the source of origin, different words in slang have different life expectancies in a sense: some get replaced relatively quickly or grow archaic while others endure and maintain a relatively constant level of usage and acceptability. One such word is "cool". Strictly reducing our discussion to English American slang, the word "cool" has been around for a while, at least according to this article. It turns out that unlike other American colloquialism with concreteness and minimal scope such as "dude", "cool" is a bit more sophisticated in that it's not only abstract at times but also polymorphic and elusive in meaning.
     From what I can remember, it was quite an accomplishment to be branded with the description "cool" back in elementary school and even middle school. It meant being someone your peers admire and even strive to emulate. This typically means being funny, approachable, friendly, and almost necessarily talented and/or attractive. When I went to high school and even now in undergrad, the description "cool" is more easily placed in others. In this context, however, being "cool" meant that you are for the most part just approachable and can maintain a somewhat friendly, maybe even entertaining, conversation. In this case being considered "cool" does not mean you are amongst the popular elites of your school or university but that you are not amongst the class of those students who may be considered unsociable, an enemy perhaps, or just highly deviant in behavior or beliefs by the socially acceptable standards. These are contexts that hopefully you can relate to. In the grown-up circle, the term "cool" when used seems to be more of an indication of youthfulness sometimes than a reference to fame or demeanor. Similarly, in different eras and different social groups, the term "cool" slightly changes meaning while still fleeting around the idea of desirability, albeit in different ways.
    So back to the question at hand: why is the word "cool" just about as prevalent and socially acceptable as long as we have known and used it? From the discussion the previous paragraph, it is apparent that "cool" is intrinsically mutable to a multitude of contexts. Further, it did not seem to originate from an exclusive group or from some obscure reference in a popular song at the time of its inception. Lastly, despite the nebulosity of the word, the fundamental idea of desirability that the word conveys gives a universally accessible vibe and affinity to the word. More specifically, given that is in our nature to be desired and respected by others, the word "cool" has stood the test of time and being desirable to others has never been "out of style". Although there have been synonyms from time to time that more specifically reference how people are or want to be desirable, "cool" has always been considered the common denominator that serves as an umbrella for all the other terms that have come and gone throughout time. So as long as people wish to be desirable, I believe the word "cool" will continue to maintain its tenure in the lexicon of contemporary American slang. What do you guy think about the word "cool"? Are there any other slang words you know that have been around for a while?