Not to put too fine a point on it, they once said that - the linked paper from Brin and Page was published in 1998, when they were still students.

Notably, though, just a few months before they launched as a commercial operation.

Reminds me of the Onion article:

https://www.theonion.com/no-way-to-prevent-this-says-only-na...

Sorry for the offtopic, but Im interested in natural Language constructs like this way of using Hmmm. after a sentence. First I thought it was something from the Portuguese speakers, after more thinking I see maybe it is common of French speakers. Or maybe is common in the U.S. too, I have been there only few times. I found it very funny, and somewhat familiar. :ps: The wonders of having a search engine at anyone's hand.

I think the linguistic term is "interjection". https://en.wikipedia.org/wiki/Interjection