Despite antitrust investigations and growing competition, Google CEO Larry Page sees the company itself as its biggest obstacle to success.

During an appearance today at Google's Zeitgeist conference in Paradise Valley, Ariz., Page was asked what he felt the biggest threat was to Google's success. His answer was a loud "Google."

"One of the interesting things that we've noticed is that companies correlate on decision-making and speed of decision making," Page said. "There are basically no companies that have good slow decisions. There are only companies that have good fast decisions. So I think that's also a natural thing as companies get bigger, they tend to slow down decision-making. And that's pretty tragic."

Page cited an early attempt to get an ad deal with Yahoo as an early failure. "We made a mistake not having enough capital," he said. When asked about Yahoo's woes, Google Chairman Eric Schmidt, who joined Page on stage for the talk, declined to say much more than, "I think they should sort our their leadership issues."

When asked about how Google will absorb its pending $12.5 billion acquisition of Motorola Mobility, which is currently facing antitrust review, Page joked that the merger will double its workforce but not its market capitalization.

"While it's significant, it's not doubling our market cap as much as we'd like it to," Page said of the acquisition, Google's largest to date. "It's relatively small in that sense."

Noting that Motorola was among the first to back Android, Page called the company a "very natural partner." He also said that with acquisitions like that of YouTube in 2006, Google has "always strived to take those kinds of risks and recognize those kinds of opportunities."

While taking questions from the audience, the pair also discussed topics such as driverless cars ("Our computers drive your cars better than you do when you're drunk," Schmidt said), as well as what may lie ahead for the company's next 13 years on the occasion of its 13th birthday today ("You'll have a Google in your pocket," Page said).

YouTube video from the event: