There are some fishing instructors who feel that you should start the sport learning to use a dry fly. When you listen to their reasons for this it seems to make a lot of sense. They say that because you can see more of what's going on, the dry fly makes learning faster.
-you can see feeding fish rise to the surface, so no guessing where they are in the stream.
-you can see what they are eating on the surface.
-you can see how your fly drifts in the current.
-coming in from behind, you can get closer to the fish & it's easier to catch a trout 20 ft away than, say, 60 ft.
As they say, these benefits are visual. Using a dry makes the beginner VERY aware of the concept of current drag & how it affects the drift of their line. Learning how to deal with drag early on in your fishing will also help in your subsurface fishing, too.
When you think about it, there doesn't have to be a hatch going on to justify using a dry fly. Trout are always looking up - both for food & predators. I know a few really good anglers who do their searching & prospecting with a dry fly. In the summertime, after all the spring hatches are over, terrestrial imitations can be very effective - ants, hoppers, etc.
Of course matching the hatch is awesome fun. I suggest (if you haven't yet) to pick just one hatch to begin with & study it. This is a great intro to entomology for the beginner. We should all have at least one local hatch we we can match perfectly. Nothing will give an angler more pride.
But you don't always have to match the hatch to catch trout on dries. There are time-tested patterns that will work almost anywhere. You know the ones I mean - they look like nothing in particular & everything in general, all at the same time. The really good anglers I know seem to never be without an Adams, Light Cahill, Quill Gordon, & a bushier fly like a Royal Wulff. These patterns seem to work wherever you are & especially when nothing else seems to be doing the trick.
Each style of fishing, surface or subsurface, has it's own set of challenges & obstacles to overcome. Different skills are needed to find success with each. An experienced angler knows when to use dries or subsurface flies - & they use dries more than you might think. For the beginner, or any angler wanting to gain experience, the dry fly can be a great help as a visual aid & show you what's really happening in & on the water. For those of you who are introducing new anglers to the sport, you might want to consider starting your students with a dry fly.