I was around 20 years old, mid 90's, and found out I had an uncle who lived in Coeur d'Alene who fly fished. We were going on a family vacation with around 30 or 40 of the family all descending on Jackson Hole and I decided that it was something I would love to try. I went and bought a beginners fly rod and reel outfit by South Bend and went ahead and purchased a fly tying kit along with a book.
Alas, there was no fishing on that trip as there was no time but the damage was done. After cutting my teeth on the local bass and sunfish population in Northeast Kansas I have fished exclusively with the fly rod ever since.
I started tying because where I live, if you want a fly, you either have it mailed to you or tie it yourself. I like gear and immersing myself in whatever hobby I am into at the time so this seemed a natural extension. I enjoyed tying but it was a means to an end to support my fishing hobby. As I have gotten older I find myself enjoying tying more and more.
I particularly enjoy tying trout flies. Something about the size and materials trying to imitate bugs fascinates me. I least enjoy tying large warmwater flies, which is a problem because that is 100% of the fishing anywhere near me. Hence my trout boxes which are used maybe a couple of times a year are overstuffed while my warmwater boxes are continually running low.