While fads come and go (and occasionally come back as retro), the availability of MTV and the internet to recent generations means that a newly-minted style can go from "in" to "out" faster than you can process your online order at PacSun, replaced by some other equally pointless fad.
So who's behind these trends that pop up and spread like wildfire? Usually, it's some damned celebrity. For instance ...
Who's To Blame: Ice-T, "Marky" Mark WahlbergFew fashion trends are so abhorred by some members of the public that they can land you in jail, but this is exactly where you can wind up if you let your jeans sag enough to expose your underwear in the town of Delcambre, Louisiana. As sagging has been said to have originated among prison inmates (due to prisoners being issued oversized clothes and not permitted to wear belts) this means that your punishment for wearing sagging pants in Louisiana could be ... a sentence to six months wearing saggy pants. Yeah, that'll deter and "reform" those saggy-pants-wearers, Louisiana!
The drooping pants started showing up around 1992, but as early as 1988, rapper Ice-T was boasting that his "pants are saggin'" (in the track "Colors") so we're blaming him for starting the whole thing since we have him on record.
Though he did show some restraint
By 1993 Marky Mark Wahlberg was doing Calvin Klein ads showing off the look, and there was no keeping it out of the mainstream.
Good job, guys. You created a trend so awful they're having to threaten people with jail to stop it.
Who's To Blame: Jennifer Aniston
This haircut worn by Aniston in the early years of Friends was voted as the "most influential hairstyle of all time" in a survey of 2,000 women though we question any such survey that doesn't include Princess Leia's earmuff hair Star Wars in the top 10.
Apparently, it's influence was limited to fans simultaneously copying the style in 1996, and then immediately dropping the style after realizing everyone having the same hairstyle as you at a party is more embarrassing than seeing just one other person wearing the same outfit.