This article was originally posted on Inc.com.

In remarks at Inc.’s annual GrowCo conference on Wednesday, the entrepreneur, investor, and Internet advocate divulged the most valuable lessons he’s learned since he launched the hugely popular website in 2005.

After many years away, Alexis Ohanian, the serial entrepreneur, investor, and open-Internet advocate, recently returned to the helm of Reddit, the huge user-curated news site, along with his co-founder and college roommate, Steve Huffman.

The two founded Reddit in 2005, sold it to Conde Nast a year later, spent several years working on other ventures–and, in Ohanian’s case, doing a lot of Internet advocacy in Washington, D.C.–before coming back to lead Reddit. Ohanian returned in November 2014 as chairman, and Huffman eight months later as CEO.

But they did so amidst big challenges. There was broad acknowledgment at the time that Reddit needed to clean up spammy or distasteful content. The site is now far more sprawling than when they left, with 230 million monthly active users who click on 8 billion pages per month.

On Wednesday, in remarks before 700 entrepreneurs attending Inc.’s GrowCo conference in Las Vegas, Ohanian spoke about the things he wishes someone had told him when he and Huffman were just starting out, two guys in an apartment in Medford, Massachusetts.

“Everything I’ve learned in the last decade as an entrepreneur and investor I learned the hard way, I learned from some of the mistakes I made as well as some of the things I did get right,” Ohanian said as he kicked off his keynote session.

1. Great founders don’t quit, but do adapt.

When Ohanian and Huffman first pitched Paul Graham of startup accelerator Y Combinator in Boston in June 2005, their idea–for a site called “Mmm”–was rejected. But as they were on a train out of town, dejected, Graham called Ohanian back. Ohanian recalled picking up the phone: “Graham said, ‘We talked about it and we still don’t like your idea. But we like you two. We believe in you two. As long as you change your idea and come up with anything else, we’ll invest in you’.”

While Ohanian conceded circumstances won’t always be as explicit as they were in this case, you will always be able to read signals about how you can change or adjust, rather than quit. Read them, he advised. He added that great entrepreneurs are not the ones who keep trying to perfect one concept the same way over and over again, but those who constantly try out new ideas, challenge assumptions, and find what actually works for users in the marketplace.

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