I visited a stack exchange site at which I have no account. I wished to ask a question, but not to associate the activity with my identity across the network. So I intentionally did not click on 'join this community.'
I was presented with a dialog offering my two choices: create an account linked to my logged-in Google identity, or cancel.
So I clicked on cancel.
And was presented with the same dialog. Rinse, lather, repeat.
Each iteration created an entry in browser history.