Since everyone else seems to be talking about how they got started...
I grew up on the NY/VT border, and went fishing with my Dad. Out of the four of us I was the only one who would go fishing with him. Dad did not fly fish, but he had an old (cheap) bamboo rod with a terrible set in the tip. Not sure why I wanted to fly fish, guess it was articles in magizines. Since I couldn't afford Orvis flies, and knew the flies in the hardware store were poor quality, I determined to tie my own. Cought my first fish on a fly I concocted with a jewler's vise, Mom's thread, yarn, and feathers from my pillow. While I was fumbling around (couldn't figure out how to do hackles) Dad told me to go see Mr. Mac (a neighbor). WOW!!! The old guy taught me all kinds of stuff, shared materials, hooks, and advise. The best advise was to go to the library, and tell the liberian I needed books That on fly fishing for trout. The next day I learned the dewey decimal system, and realized I could learn anything I wanted in the library. That knowledge has served me in every endever since. Took the books to Me Mac, and he told me what to read, and what to take back. That included TROUT, by Ray Bergman, of course. He also gave me his old HERTERS catalog. That became my "Wish Book." I was running a trap line then, and had a hunting license, so Mr. Mac got all of the fur and feathers available in the local woods. I'm sure he never used 10% of what I supplied him with, probably threw most of it out, but accepted it with the most gracious thanks. No, I didn't catch a lot of fish, dam few as I recall, but enjoyed myself none the less.
When I was 16 we moved to Boston, and I couldn't get to a trout stream. Then girls, drugs, cars, college, money, and rock and roll were more important. Dug the stuff out in my mid 20s but only cought chubs. Then the kids came, and the divorse, and then I was a single parent. When my son finally left home, I moved to a camper on a lake, and stayed for 5 years. Had to start from scratch, as my ex-wife sold all of my fishing stuff in a yard sale. For 2 years I worked part time, and fished full time. After 2 years my estranged daughter arrived with her daughter. Three yaars later she left (new boyfriend), without the daughter. This must seem long, but I'm leaving out a lot of gory details. I'm in an apartment now with the grandaughter (Arwen, 5 years) and Anne (she's retired Navy, with a vocabulary you wouldn't believe). During all of this I read every book I could find on on fly fishing. I'm probably the best read, and least experienced fly fisherman here.
To answer the origional question...
Of all of the fishing I have ever done, success in fly fishing for trout depends mainly on skill. Most other fishing is more luck than skill, besides...
"Its the most fun you can have standing up."