I have always loved animals, especially horses, since I was little. I always pretended I was either a horse or a wolf at recess in elementary school, and it's grown from there. I didn't know about furry fandom until about 4 years ago, but when I was around the ages of 10-16 I played online forum based role play games where I was a horse. I had several characters, and was very sad when my favorite site got shut down. It sent me into such a fury that I quit RPing all together. I haven't been able to find a site like it again.
Overall I realized that it was okay to feel the way I feel and do the things I do. Like relate to animals more than people, and especially think the way that I think. So I guess I could say I've been a furry all my life, but just didn't know it had a name until a few years ago.