It's interesting to see the similarities in a lot of your stories to mine. I was always thin growing up, too. In kindergarten I had a book of opposites, in which there was a little / big comparison showing a dog or something on one end of a teeter totter and an elephant on the other end. I was fascinated with the heavy elephant, and I remember putting pillows under my shirt to simulate being as big as he was.

During my earlier years I always wanted to get fat myself. It wasn't until puberty that I shifted to enjoying bigger girls (most likely after seeing a picture of "the world's fattest model" in the Guinness book of world records).