Sep 18, 2014 · 1 minute

"If you invested in every one of the ten next best VC investments, but you miss a Facebook or a Google, the next ten don't add up to even one of a Facebook or a Google."

Thus is the nature of regret in the venture capitalism world.

That quote was just dropped by Bessemer Venture Partners' Jeremy Levine at tonight's PandoMonthly in New York. Levine has had plenty of successes: Pinterest, Yelp, and LinkedIn, to name three. But the investment he'll never forget is the one he didn't make: Facebook.

In the summer of 2004, when Mark Zuckerberg split the East Coast for Palo Alto (looks like fun!), Levine was invited to speak on a panel at a leadership seminar run by his wife in New York. All weekend, some fresh-faced youth named Eduardo Saverin, then the CFO of a Harvard-based social network for college kids, followed Levine around, pleading with him to invest.

Upon hearing Saverin's initial pitch for "The Facebook," Levine's response was priceless:

"Kid, haven't you heard of Friendster? Forget about it."

Levine would be lying to himself if he said he didn't regret the decision to pass on Facebook, particularly at that early stage. In darker moments he's asked himself questions like, "Had it been Mark Zuckerberg who I bumped into, had I thought about it differently?" But in the end, regret is about the least productive emotion you can feel as an investor.

"As soon as you identify the patterns of today, the patterns of tomorrow change," Levine says. "You have to keep focused on what's around the corner."

Still, a billion dollars would have been pretty cool.