Mark Zuckerberg took on the public Thursday, holding his first-ever open Q&A session.
The Facebook CEO spent about an hour answering questions submitted from around the world, including some from Facebook users who flew to the company's California headquarters for the event.
Here's a look at some of the highlights:
Why did Facebook force its users to install the Messenger app?
Zuckerberg acknowledged that having all Facebook users install a new app "is a big ask" and "required friction."
"On mobile, each app really can focus on doing one thing well, we think," he said.
"You're probably messaging people 15, 20 times a day, and having to go into an app and wait for it to load and then go through a bunch of steps to get to your messages or send a message is a lot of friction."
How accurate was the movie The Social Network?
"I haven't spent a lot of time thinking about that movie in a while," Zuckerberg said with a laugh. "I kind of blocked that one out."
"I think the reality is that writing code and then building a product and building a company actually is not a glamorous enough thing to make a movie about, so you can imagine that a lot of this stuff they had to embellish or make up."
"They went out of their way in the movie to try to get some interesting details correct like the design of the office, but on the overarching plot... they just kind of made up a bunch of stuff that I found kind of hurtful."
He noted that the film suggests that he built Facebook after being jilted by a girl, but that in reality, he's been with his wife since before staring the site.
"There were pretty glaring things that were just made up about the movie that made it pretty hard to take seriously," he said. "I think the real story is just a lot of hard work."
Is Facebook becoming too boring, and are you worried about it getting cluttered with photos and video?
"My goal was never really to make Facebook cool," Zuckerberg said. "I am not a cool person, and I've never really tried to be cool. Our model for Facebook has never been to try to make it particularly exciting to use -- we just want to make it useful."
"The services that we aspire to be like in the world are kind of these basic things that you rely on," he said, citing electricity as an example.
As for the look of the site, Zuckerberg said it was largely dependent on the type of content users choose to share.
"Five years ago most of Facebook was text, and if you fast forward five years, probably most of it is going to be video, just because it's getting easier to capture video and the moments of your life and share it," he said.
Why do you wear the same grey t-shirt every day?
"I really want to clear my life so that I have to make as few decisions as possible about anything except how to best serve this community," Zuckerberg said, referring to the Facebook user base.
"I'm in this really lucky position where I get to wake up every day and help serve more than a billion people, and I feel like I'm not doing my job if I spend any of my energy on things that are silly or frivolous about my life, so that way I can dedicate all of my energy towards just building the best products and services."
What's the importance of diversifying the tech sector?
"There's just so much research that shows that diverse teams perform better at anything you're trying to do," he said. "Companies that are more diverse do better."
Not only is there less diversity in the tech sector than normal, he added, "but there's especially way fewer women."
"It's this problem because it's not even clear where you would start attacking it. You need to start earlier in the funnel so that girls don't self-select out of doing computer science education, but at the same time, one of the big reasons why today we have this issue is that there aren't a lot of women in the field today."
"I heard one person put it, 'The reason why girls don't go into computer science is because there are no girls in computer science... you need to break the cycle."
Zuckerberg then passed the mic to Facebook chief operating officer Sheryl Sandberg, whose book Lean In addresses the challenges women face in the professional world.
Sandberg cited the example of the computer science education program Girls Who Code, calling it "the answer."
"We know that girls are just as good at math and science when they are told they are just as good at math and science," she said. "It's really simply a matter of expectations."
Why is Facebook getting involved in the fight against Ebola?
"We're at this critical moment in time right now," Zuckerberg said, adding that Ebola "could be the next global epidemic -- the next HIV or tuberculosis or polio."
"I think there isn't enough attention in the world focused on stopping those things before they become at that scale," he said.
How did you overcome the obstacles you faced in building Facebook?
"When I was getting started, I didn't want to build a company and I didn't know anything about building companies," Zuckerberg said.
"The thing that got me through it and I think gets a lot of people through it is the people around them.... Companies that have more founders are actually more likely to have a successful outcome, and one of the reasons for that I think is it's just really hard to do anything on your own like this."
"One of the things that I think the media gets wrong about companies or inventions or things over time is they try to make it seem like one person did it."