I do this sometimes too, which is usually when google instant works for me, like when I've visited a page a bunch of times, but I can't be bothered to bookmark it or save the search in some other way, and I know it will come up easily in the first page of results- I just want to get to a page super fast, and it's not a url per se, but something specific I searched for and need again.

I'd say most times I search through my chrome bar, but sometimes I do end up on the google page for whatever reason.