If you know what the mend is and how to do it, you have probably learned to catch more fish. Trout are generally bright (or instinctive) enough to know the subtleties of the current and how fast or slow a bug should be drifting. If your fly is being dragged by the current at an unnatural pace through a big loop or kink in your line, then a wild trout or, at least an experienced one, is far less likely to offer you a take.
However, another point in fine-tuning your skills is that, once your fly is drifting in place with the desired current, you want it to remain as undisturbed as possible. This means mending with a big flip or a snatched loop is a bad idea and can spook the warier (and often bigger) fish. Instead, you want to gently lift your fly line out of the current and move your rod upstream, placing the fly line gently back down behind the fly’s drift. This allows the least disturbance of your fly’s natural drift and can often mean the difference between netting a lunker, just a yearling or nothing at all.
Thanks for reading.
From the water’s edge,
Daniel