Fellas, I respect all of your opinions and I enjoy learning from them as well.
One thing to think of...Any pattern you throw and catch fish on is mimicking some type of aquatic activity or stimulating a reaction from trout. The patterns that generally work the most are in tune to the recent benthic activity.
That being said; what feeding trait tells the trout when it is time to start taking dry flies(?) In my opinion, it is an increased presence of emergent nymphs and actual adults on the water. There are correlating factors that trout could unknowingly relate as well-such as temperature, sunlight %, pH, oxygen content, etc...However; I think these factors are less influential than the basic desire to feed. As of recent; I have not witnessed any massive hatches. Most are limited and consist of a dry floating by every minute or two...So; it is very easy to repetitively induce a dry fly in to a feeding lie to simulate a hatch.
Fortunately; my personality is inventive and open to learning. I could not imagine fly fishing with 2-3 patterns and find that stimulating. But, that is the beauty of life and in choosing a fishing partner. I generally surround myself with positive and innovative people. Most of all; I shun negativity with a passion as it will eventually poison the soul and all those around it...
I Like this quote and I hope it some may enjoy it as well...
"We all operate in two contrasting modes, which might be called open and closed. The open mode is more relaxed, more receptive, more exploratory, more democratic, more playful and more humorous. The closed mode is the tighter, more rigid, more hierarchical, more tunnel-visioned. Most people, unfortunately spend most of their time in the closed mode. Not that the closed mode cannot be helpful. If you are leaping a ravine, the moment of takeoff is a bad time for considering alternative strategies. When you charge the enemy machine-gun post, don't waste energy trying to see the funny side of it. Do it in the "closed" mode. But the moment the action is over, try to return to the "open" mode—to open your mind again to all the feedback from our action that enables us to tell whether the action has been successful, or whether further action is need to improve on what we have done. In other words, we must return to the open mode, because in that mode we are the most aware, most receptive, most creative, and therefore at our most intelligent."— John Cleese.