The following is a foolish commentary, and should not be taken seriously. For that matter, it should not be read by anyone.
Among certain teen subcultures, the term "random" is applied to almost anything spontaneous that occurs (usually during a conversation), even if the event is not random at all. Additionally, these same subcultures often have an uncanny fondness for anything they perceive to be random, as a substitute for actual wit or humor.
Although they describe the events as random, there is often a distinct pattern to their conversations. Sexual innuendos, lines from favorite television shows, and inside jokes often feature heavily, and it may seem to the innocent bystander that these lovers of "randomness" are attempting to behave as if their lives were actually anime story lines. The truth, sadly, is far more sinister.
The real reason these goofy, hyperactive teenagers adore their faux randomness so much is that they are mentally incapacitated in two ways. Firstly, popular culture has a detrimental hypnotic effect on these poor teenagers' minds: their attention spans rarely exceed eight seconds, and therefore they feel compelled to re-stimulate group activity by saying something unrelated to whatever they have been talking about for the last eight seconds. Their broken conversations are not the result of pure stupidity, but rather an inability to maintain focus.
Secondly, their imaginations are dulled by the images and ideas they are exposed to every day, on television and on the internet. They have come to mistake memes with creativity, and the part of their minds that truly has the capacity to be spontaneous and random is atrophied. In their desperation, they turn to these trite and overused ideas for their eight seconds of conversation, delighting every single time one of them comes up with another one. This delight is expressed through laughter, exclamations of "WTF," and saying "That's so random!"
People should have sympathy for these twice-damned souls, for they are but victims of peer pressure and mind-dulling influences. The truly intelligent, creative, and humorous should not scorn them, but make it their goal to gently ease these poor, ignorant fools out of shallow-mindedness. Improv comedy is a wonderful tool for this, since the concept is attractive to them ("It's a form of comedy where you get to be random!"), and encourages creative silliness in place of memes ("Actually, try just going with whatever pops into your head, rather than quoting from a funny movie").
Failing that, the truly intelligent, creative, and humorous can always become famous icons of popular culture, and provide more material for the eight-second-long conversations. That could also work.