There can be no doubt that social media is essential to understanding and reporting on what's happening in the world today. 

But there's also no doubt that a lot of what spreads around on Twitter, Facebook and other sites is tremendously trivial, utterly fake or otherwise a complete waste of time and energy. 

#DeadRaccoonTO and #PizzaRat

It's often said that cats rule the internet, but other animals gave them a run for their money in 2015. 

In Toronto in July, a humble raccoon, likely barely noticed in life, gained international attention in death. The dead raccoon was reported to the city one morning, but remained untouched for hours. 

In that time, the trappings of a mock funeral began to appear. A framed photo. Flowers. Cards. A book of condolence. Eventually, candles. And, of course, a trending hashtag — #DeadRaccoonTO — leading to worldwide media attention. 

But an ironic vigil to Canadian roadkill can't compete with a live rat carrying an entire slice of pizza down a flight of stairs in a subway station in New York City. 

#PizzaRat's 15 seconds of video got millions of shares on Twitter and Facebook, international media coverage and a bit on The Late Show with Stephen Colbert

#MerryChristmasStarbucks

Sometimes, it seems as though people on social media can get outraged at even the smallest things. The New York Times took heat for a recipe for guacamole that included peas, for Pete's sake. 

More recently, Starbucks faced criticism for the design of this year's holiday coffee cup. Previous cups have included rather generic festive motifs: snowflakes and such. 

This year, they decided to go with a simple bright red cup. Some Christians took that as another salvo in the War on Christmas. Even Donald Trump called for a boycott

Most people, though, didn't see why the minimalist design, free of secular holiday symbols, was an attack on anything. The hashtag #ItsJustACup was a worldwide trend. 

Another worldwide trend this year was #BoycottStarWarsVII. The idea was that certain Star Wars fans were going to shun the new sequel because it has actors in prominent roles who aren't white. Cue the internet outrage. 

Of course, there was no such boycott and the point of the campaign was to troll people and create that outrage. Star Wars: The Force Awakens, meanwhile, is set to break box-office records. 

Mother of all time wasters

But without a doubt the year's biggest waste of time, eating up years and years of humanity's collective attention span, was The Dress

If you're blissfully unaware of this internet phenomenon from last February, count yourself lucky. You missed the endless debate over whether a photo of a blue and black dress actually depicted a white and gold dress. 

Here's a clip from The National with two colour experts at a textile lab in Edmonton. 

The Dress spread like wildfire over every social network. It divided households, friends and colleagues, and soon overwhelmed the poor Tumblr user who posted the original photo. Companies jumped on the viral bandwagon with, frankly, embarrassing attempts to link the debate to their own corporate colours. 

Journalists wrote complex explanations of how people could disagree about something so simple as the colours shown in a photo. Differences in human colour perception. Screen brightness and room lighting. 

Twitter counted The Dress among the most memorable moments in 2015. In two days at the end of February, there were more than 4.4 million tweets posted about this debate. 

So, yes, much of what trends on social media is nonsense. But you can't really blame Twitter or Facebook for that. After all, the trends just show us what we are talking about. And you never know what weird little thing will capture people's imagination.