Building the largest social network in the world came with its own set of challenges, and Mark Zuckerberg can attest to making a few mistakes along the way. But the Facebook founder doesn't spend too much time dwelling on them.

"Mistakes are how you learn," he said at the Facebook headquarters in Menlo Park, Calif., Thursday, during a Q&A session with Facebook employees that was livestreamed to the public. "The majority of what I've done has been mistakes. You get to be successful by getting a few things right." 

Facebook holds such "town hall" meetings weekly, where employees can ask Zuckerberg anything about the company's vision and day-to-day strategy, and occasionally opens up the forum to questions from users via the web.

One recent mistake the Facebook founder mentioned during the session was this summer's controversial experiment in which users' News Feeds were intentionally tweaked to manipulate emotions. Critics found the experiment "unethical" and said that Facebook's data science team had gone too far.

It's not uncommon for Facebook to run surveys and beta tests to see how their users react to new features on the platform, but Zuckerberg admitted that some experiments require more careful internal evaluation.

"If someone is testing [sensitive information] internally, the right people inside the company need to oversee it and that's what we're going to do now," he said.

According to Zuckerberg, spending less time dwelling on past mistakes gives him the time to focus on being a proactive leader instead of a reactive one. "There are enough things that happen throughout the day that that I can spend all my time reacting, but I choose instead to proactively work on the things I want to see happen," he said.

One of Zuckerberg's recent proactive endeavors: teaching a local after-school program on entrepreneurship.

"I ended up learning more from these kids in middle school," he said.