I have a site that includes lots of older content. I checked the first page that came to mind (published in 2005) and it still shows up on the first page of Go

I have a site that includes lots of older content. I checked the first page that came to mind (published in 2005) and it still shows up on the first page of Google results for the obvious search terms. So it certainly isn't as clear-cut as 'everything older than 10 years is not in the index'. update checked another circa 2003. It's also on the first page of search results for a search on its title.