People come to things by circuitous routes. I have heard of more than one person who got into paleontology through art; they started out by drawing dinosaurs and graduated to studying dinosaurs (not everyone makes that transition...).
I sometimes wonder if I will eventually become a birder. This thought first came to me when I was ODing on natural history a couple years ago. I dig watching animals, pretty much without reservation. I have a big aquarium and keep fish, for most of my life I kept turtles, and every time I've bumped into an animal--okay, a vertebrate--outdoors I've observed it with great interest, regardless of exactly what kind it is. You can go fishing and you can go herping, but those require going where the fish and herps are, and even then there's no guarantee you'll see any. You can't usually just "go mammaling" because usually mammals are either absent or laying low. But you can walk out the door just about anytime and see birds. So it seems reasonable to me that someone with a broad interest in watching critters might end up as a birder because birds are there to watch.
Any committed birders out there are probably appalled at my lack of passion. In which case, hold on, you ain't seen nothin' yet.
Over the holidays I blew a hundred bucks worth of Christmas money on a spotting scope. Partly because I'd always wanted one, partly because I intended to use it as a travel telescope for those dark Oklahoma skies (a successful venture, I might add). Today I was just monkeying around with it and decided to try taking some pictures of birds in the back yard. I didn't get any birds, but I did get some good pix of the neighborhood squirrel. If I do ever become a birder, it will be at least partly because I enjoy--in the immortal words of Mike Taylor--badgering around with telescopes.
UPDATE: I'm not alone! "I took my very first bird photograph through my astronomical telescope in 1998."
Taken by afocal projection using a Celestron C70 spotting scope, Orion 32mm Plossl eyepiece, and Nikon Coolpix 4500 digital camera.