Suddenly, with just a morning of interaction with an instructor, everything just clicked!
That can happen , sometimes very quickly, sometimes never. I think the sooner a newcomer gets some instruction, the better chance he has of this happening. That is providing he doesn't have expectations of being able to cast a fly after 30 minutes as far as the guys he's seen casting off the jetty with shooting heads.
Of the last three guys I've given instruction to, two of them increased their distances at least 3 fold inside of an hour. Both were fanatic fishermen determined to learn to fly fish.
One had no previous experience at all fly fishing, and showed up with his own rod. It was a very good, used, no-name rod he had just bought that was underlined three or 4 line weights.
The other guy I'd fished with a few times and was very good with spinning and plug casting conventional gear. He was going salmon fishing with business associates and had only fly fished with light gear in small brooks. He said he could not cast nearly well enough to river fish for Atlantics. He was right at the beginning, but wrong an hour later - assuming he practiced ocassionally during the ensuing months before the trip.
The third guy is a neighbor , and I think he expected to be able to cast the whole line after a half-hour. He just couldn't get it quickly, and has not tried since, to my knowledge.
Everyone's different, but what seems like a miracle can happen quickly for many. And the cost,in time, to find out if you're one of them is only an hour or two; in money, at most, the cost of a meal for two at a good restaurant.