When I was a young child, I showed signs of being a furry or therian of sorts. I recall once, when I was about five years old, seeing my occupational therapist, and trying to convince her that the robe tie in my pants was a tail I'd grown overnight. As silly as this was, I think it meant something for me. I felt like I should be more animal or have a tail of sorts. (Even if bonobos don't have tails, hehe.) I've always behaved a bit more animalistically (growling and snarling naturally and instinctively, etc.), and from a young age, I enjoyed drawing furry art...long before I knew it was actually a real thing. When I was fourteen, I joined the therian community, and while I still consider myself some sort of variant of therian, I never quite fit in that community. When I was 18, I learned more about furry and what it was as well as how it differed from therianthropy. I attended my first furry convention when I was 19. Soon after, I began to consider myself both a furry and a therian.
Now I'm active in both communities, but mostly in the furry community. I see furry and therianthropy as very similar. As one friend once put it, "It's just Trekkies versus Trekkers. One community is a bit too serious, and the other is a little more lighthearted about it, but it's the same thing." I had initially argued that they were two very different communities, but the more I immerse myself in furry, I realize that our connections to our fursonas are often just as deeply set and ingrained, as a therian's connection to their theriotype.
So, if this was a bit too long to read, "tl;dr": I was always very animal, and found therianthropy first, and then branched out into furry.