I just earned the Autobiographer badge to go with my Yearling badge.
It was my own fault really: I filled in my profile.
It bothers me a little because I thought that having no other badge than Yearling was unusual.
Is that right?
You fulfilled the requirements for the two badges mentioned so they were awarded to you. Why does that confuse or bother you?
As for the Yearling badge being the one and only, I suspect that applies to a fair number of others. Many people come to the site, post a question or answer or two and disappear. If they get the required 200 points, after a year they get the Yearling badge. Not unusual at all. It's just that in your case you've come back.
meta
at the top of the SF page, I was informed I had a yearling badge. It does make sense, though that the 'drive by posters' (as I like to call them) with no badges, outnumber regular visitors.