Going by your logical explanation, then I would say I have also worked as a Virtual assistant without even realising I was working as one.
There was this one time I was hired to do a data entry job for a firm. It was a remote job and it involved me copying some data and correctly arranging them on an excel file. Then I didn't exactly associate what I was doing as anything remotely close to a virtual assistant. Now that I have come to think about it, I have realized that at that point I was effectively working as a virtual assistant.