Jay Maidment/Marvel

When Joss Whedon quit Twitter on Monday just after the "Avengers: Age of Ultron" US premiere, speculation abounded as to why the opinionated director left the social-media service so abruptly.

Did it have to do with his tweet calling a "Jurassic World" clip "70s-era sexist" -- a tweet that he later told Variety he regretted sending, reconsidering his own actions as "bad form"? Did he abandon Twitter after being harassed for posting support for GamerGate target Anita Sarkeesian? Some fans blame feminists criticizing the director for his depiction of Black Widow (Scarlett Johansson) as more of a damsel in distress rather than a sassy superhero who can hold her own in "Age of Ultron."

The truth, the busy filmmaker said, is that bullies and disappointed feminists had nothing to do with his leaving the social-media platform.

"Twitter is an addictive little thing," Whedon told Buzzfeed, "and if it's there, I gotta check it. When you keep doing something after it stops giving you pleasure, that's kind of rock bottom for an addict. I just had a little moment of clarity where I'm like, You know what? If I want to get stuff done, I need to not constantly hit this thing for a news item or a joke or some praise, and then be suddenly sad when there's hate and then hate and then hate."

Whedon didn't respond to CNET's request for comment.

There's a darker side of fandom that celebs are usually sheltered from until they go online.

This isn't the first time a celebrity has left Twitter to focus more on his or her own career than tweeting. Last year, "Sandman" writer Neil Gaiman took a social-media hiatus for six months to concentrate on his day job as a writer.

But while some high-profile tweeters ditch Twitter for productivity reasons, others can't handle the constant onslaught of hate in 140 characters. There's a darker side of fandom that celebs are usually sheltered from until they go online. Some fans like to pick fights or insult celebs at the lowest level. Others just want constant attention.

When comedian and actor Robin Williams died, his daughter Zelda Williams was attacked by trolls who sent her gruesome Photoshopped pictures of her dad. So she left Twitter. Eventually she returned to social media, but clearly its dark side was hard to ignore.

British comedian and actress Sue Perkins left Twitter last month after receiving numerous death threats from "Top Gear" fans who were upset over the speculation that she might replace Jeremy Clarkson as the show's host.

Then there are celebs who leave Twitter because the experience is no longer a fun way to connect with fans. Comedian and actor Louis C.K. left Twitter this year because he kept regretting all his tweets, which would then throw him into a downward depression spiral.

"It didn't make me feel good," he said. "Every time I say anything, I wish I hadn't said it. Reading it depressed me and writing it depressed me."

Actor Simon Pegg handed over his personal Twitter account to his official fan club last year because he wasn't having fun interacting with people online anymore.

"I've decided to give Twitter a break for the time being," Pegg posted on his official website. "If you're reading this, you may be looking for an explanation as to why, so here it is. I haven't been enjoying it for a while now. There hasn't been a specific incident and the reasons are various. Ultimately, I think we've just grown apart. What I'm saying is, it's not you, it's me."

And it's not just Twitter that runs the risk of disappointing celebrities. British comedian and actor Stephen Fry recently left Instagram after being "hounded off" by fans. He briefly left Twitter because he said he felt unsafe there.

While it might be hard to imagine what life is like for celebrities who are under constant scrutiny by peers, critics, haters and fans, it's something we can, hopefully, all empathize with. No one likes to hear demeaning comments. Insults damage your self-esteem whether you're Normal Joe bus driver or Joss Whedon big-time movie director.

Celebrities aren't on Twitter to perform for us like dancing monkeys.

As fans, it's up to us not to take it personally when our favorite celebrity doesn't answer our tweets. Celebrities aren't on Twitter to perform for us like dancing monkeys. They're online to check out the news, cat videos and funny memes just like the rest of us. Twitter is not a 24/7 Q&A session where they're required to chat with every single fan who pings them.

And as much as online forums give us a sense of anonymity, that doesn't mean we should be jerks. Most of us wouldn't walk right up to a celebrity, or any stranger, and insult them to their face. So why do we feel the need to do so on Twitter? What right to we have to make someone else's day miserable just because we didn't like their movie, TV show, book, comic or podcast?

In response to Whedon leaving Twitter, even "Guardians of the Galaxy" director James Gunn posted on Facebook a plea to his fans to "be a little kinder, on the Internet and elsewhere."

Twitter

Granted, Whedon left Twitter to concentrate on his work, not because of pesky trolls. But that doesn't get us off the hook entirely. We have to remember that while Twitter can be a fun tool for sharing information and opinions, it can conversely be an online version of Mos Eisley Cantina from "Star Wars" -- a "wretched hive of scum and villainy."

It's up to us to resist going to the dark side every time we disagree with someone on Twitter. We always have that choice to immediately lash out at strangers when our buttons are pushed or take a breath before responding. We can consider the reactions of our actions before we take them. We can think before we tweet.

While some celebs take short breaks from Twitter to work on projects but eventually return, it doesn't seem Whedon will be tweeting again anytime soon.

"I need to go out, do the research, turn the page, see the thing, hear the music, live like a person; I'm not great at that," Whedon told Buzzfeed. "So, oddly enough, because I always feel like I'm the old man who doesn't get the tech, right now I'm the man who thinks he could do better without it."

As a big Whedon fan myself, I will feel his loss on Twitter. He was inquisitive, insightful and above all, funny. I checked his Twitter often when I needed a break from depressing real-world news headlines or just to procrastinate my own deadlines. I would get giddy when Whedon chatted on Twitter with actors from "Buffy" and "Firefly." He was a breath of fresh air on Twitter and will be missed terribly.

When learning of Whedon's departure from Twitter, "Doctor Strange" director Scott Derrickson summed up many of our feelings in a hopeful tweet that I wish I could retweet a million times.

"We believe he's gone to a better place, and that perhaps one day we will see him again."