How I Met Your Mother was a fun sitcom. Not only was it hilarious (as all sitcoms should be), but it contained a ton of intriguing elements not seen in most sitcoms, including an overarching mystery element and captivating time jumps. As such, it was one of the most fun TV shows to discuss while it was on the air. And as with most discussions, the theories ran wild.

RELATED: 10 Most Iconic Phrases From How I Met Your Mother

Some were great. Some were...not so great. But all were fun to read and ponder. These are five fan theories that make perfect sense and five that would never happen.

Make Sense: The Mother Is Not Around

A lot of sleuths discovered one thing - Ted never mentions The Mother as his "wife." She's always "your mother." This led some viewers to speculate that Ted and the mother had divorced in the interim or that Ted raised a one night fling's children and was recounting the story of the mother they never knew.

Amazingly, these internet sleuths turned out to be correct! Sort of. The Mother was not divorced from Ted but had in fact passed away before the events of the present-day narration. We're still counting it as correct!

Never Happen: The Characters Don't Look Like The Actors

Let us explain. Some people believe that Ted serves as an unreliable narrator because he constantly forgets various things, including character names and the fact that Lily was pregnant.

Because of this, some people thought that Ted was misremembering what his friends looked like and that the real Marshall, Robin, Lily, and Barney didn't look like Jason Segel, Cobie Smulders, Alyson Hannigan, and Neil Patrick Harris. Of course, this was total nonsense and was proved in the present-day sequences when the characters looked like older versions of their past selves.

Makes Sense: The Doppelgangers Represent Desires

Marshall plays piano for the gang as Barney holds his face in pain

As you know, doppelgangers are not real. Sure, people definitely look alike, but a perfect 1:1 ratio is simply impossible due to genetics and DNA. As such, the gang's doppelgangers aren't literal, but visual representations of their desires.

Lesbian Robin is the masculine Robin her father wanted. Mexican Ted is a more masculine and confident version of Ted. Mustache Marshall has the mustache that Marshall can't grow. Stripper Lily represents Lily's desire to get away from responsibility and motherhood. And of course, Fertility Barney gets to...examine women all day every day.

Never Happen: Barney And Robin Are Dead

The viewers may have pinpointed The Mother's death, but they were way off when it came to Barney and Robin. This theory stems from the simple fact that Barney and Robin are not present during Ted's flash forward lakeside sequences.

Marshall and Lily are there, as are Ted's various girlfriends. But no Robin and Barney. Viewers began to speculate that the two were dead in the present day, but this only proved to be more nonsense. Both Barney and Robin are very much alive, and Ted even returns to Robin in the show's final sequence.

Makes Sense: Barney Isn't Actually A Womanizer

We learn in the final episode that Ted is still pining after Robin, even after his wife's death. This has led some viewers to speculate on an interesting idea. Ted is far from a reliable narrator and he isn't above exaggerating certain aspects of the past for comedic effect (like when Robin and Barney let themselves go in season five).

RELATED: How I Met Your Mother: Barney’s Absolute Worst Play

What if he lied about Barney being a heartless womanizer in order to make his competition look worse than he actually is? This seems to be proven in the final episode, as Barney clearly loves his baby and wishes to stand by it. Ted's Barney would have been out of there in a heartbeat.

Never Happen: Ted Has Alzheimer's

This theory goes with the whole "the characters don't actually look like they do because of Ted's memory" theory. As we've established, Ted clearly doesn't have the greatest memory. He constantly forgets names and misremembers certain events, and while those can be excused, you'd think he would remember the time his best friend was pregnant!

The answer is obvious - Ted is suffering from Alzheimer's and wishes to tell the story of the mother before he forgets it. Of course, there's nothing actually indicating this within the text of the show, so we're calling baloney.

Makes Sense: Barney Wanted A Child

barney and ellie in how i met your mother

Furthering the whole "Barney isn't actually such a bad guy" thing is the possible fact that Barney actually WANTED a child. This theory hinges on the idea that Barney is infertile, which makes sense when you consider how many women he's slept with and failed to impregnate!

Like Robin, he eventually matured and realized that he wanted children, so he sought out a closed adoption so he didn't have to meet the biological mother. Not wanting to look like a "wuss" and to keep up with his womanizing charade, he tells everyone that it was an accident from a one night stand.

Never Happen: Friends Is Tracy's Imagination

Stay with us, because this one gets a little complicated. One Reddit theory posits that Friends is actually the imagination of a dying Tracy. Wanting to insert herself in her husband's story and early life, she concocts a fictional story to represent Ted and his friends. She's Phoebe (the outsider), Barney is Joey (the single womanizer), and Marshall and Lily are Monica and Chandler.

Furthermore, the theory posits that Tracy realized that Ted loved Robin, so she made the loving but on-again-off-again Ted and Robin into Ross and Rachel. Or they're just two similar shows. That works, too.

Makes Sense: Barney And Marshall Were Best Friends

Marshall, Ted, and Lily hugging in How I Met Your Mother.

Ted is an unreliable narrator, but he can also be a bit of a conceited jerk. Throughout the series, both Barney and Marshall fight over who is Ted's true best friend. It makes for a funny recurring joke, but what if it's all in Ted's head?

RELATED: HIMYM: 10 Worst Things Ted Has Ever Done

What if Barney and Marshall were the real best friends and Ted, being a jealous and conceited jerk, wanted to be seen as more important and more liked than he actually was? Hence, in his personal retelling of the events, he makes himself the center of attention.

Never Happen: The Kids Weren't Real

The final episode of the series was highly divisive, and many people hated that the entire story was blown over in a matter of seconds so Ted could once again chase after Robin. As such, some fans have done a little retconning and convinced themselves that the kids were never real.

In their minds, the kids were simply a narrative device and Ted was actually talking to himself as a means of sorting out his problem with Robin and finding a solution. Sadly, nothing indicates that this was the case. Sorry guys, but the ending just sucked.

NEXT: How I Met Your Mother: Every Main Character, Ranked By Funniness