I had a similar experience over a month ago. I was fishing the pond where I work. Using poppers, catching LOTS of Bluegill and Hybrid sunnies. One of the residents was there, a nice 80-year old retired Dentist, fishing with soft plastic worms and grubs. He wasn't catching anything, but was watching what I was doing intently.

A week later, while I'm serving lunch in the dining room, he comes up to me, and asks me if I could show him some pointers on using a fly rod. He had just bought a 7 1/2' 5wt White River Dogwood Canyon from the local BPS. I agreed.

We got together the next day. By this time, the intense heat wave had set in, and the fish went deep. He was trying to use poppers, but wasn't getting any hits. I think I caught one, on a Bead Head Wooly Bugger.

I haven't had someone tell me "you aren't going to catch anything with that here" at the spot I normally fish. There are a LOT of fly fishermen that fish that spot, so most folks are used to it by now.