It all started when I was very young. I've always loved bats. Probably, one of my first "encounters" with bats was when my parents read the book Stellaluna to me. I definitely loved bats then, and I know I loved bats at around age nine or ten, when I read the book Silverwing. I've always collected bat merchandise (plush, books, toys), and loved going to the zoo to see bats.
It wasn't until recently that I saw this, however. My love of bats was never exactly an obvious "I love bats" more of a subtle feeling. Yet when I learned of therianthropy, my first reaction was "I'm a bat", which changed soon when I was "told" I wasn't. This was, of course, long before I learned that no one can tell you what you are.
It was a couple years later that I attempted scrying. In the mirror, I saw the shadows on my face form a bat like appearance with very obvious fangs and large ears, however it appeared to have a "mane", so I just assumed that it was a lion, as that was what I kept seeing in my meditations. These images kept showing up in the mirror, though.
Another year or so later, I was trying to seriously figure out my theriotype. I felt small, rodent-like, so I thought perhaps I was a rodent. I didn't know how close, yet so far, I was then.
Not long ago, when I finally realized I might have a bat theriotype, I was swinging on a swing. I got to thinking that cave myotis did not feel right, although I was pretty sure I was a microbat, since I use my ears far more than anything else (echolocation). It was then that my train of thought went from loving the rainforest my whole life, and loving warm climates and caves, to wanting to fly, wanting to drink blood when young/drinking blood from steaks (which may or may not relate), and having urges to bite/scrape toes. It was then that I had my "Holy Shit!" moment. I realized I may very well be a vampire bat. When I looked them up, I found another interesting detail: They tend to roost near banana plantations. I have always been fascinated by banana plants, and feel at home with them.
Piecing everything together, then, did not take much time needless to say. The only question remaining is my exact subspecies. :)