Exactly. And it shows up in the data too. Are we *really* supposed to believe that Gentoo in 2004 was more "popular" than Ubuntu in 2010? That doesn't pass the stink test.
Assuming that fact is true, the only way it can be explained is if each Gentoo user had (for some inexplicable reason...) to do many times the google searches about Gentoo than the average Ubuntu user had to do for theirs.
I don't know how you can justify the idea that google searches are proportional to popularity, unless you are willing to say that an individual person's like of something is proportional to the number of times they google it.
And I'll finish by saying that I'm sure I've googled Gentoo Linux more than I have Ubuntu or Fedora, wheras I've installed the later two on a dozen or more computers, wheras the former on exactly 0.

If you're in the east bay, you might want to stop by the Valley Life Sciences Building (usually abbreviated VLSB) and their Paleontology Museum on the UC Berkeley campus. They have a lot of cool stuff, although for most of it not necessarily from a child's perspective. However, what they *do* have is a full sized assembled T-Rex, which is pretty impressive to see, for curious children of all ages.