Once anglers achieve success with streamers, they often focus intently on fishing big flies. The reason is simple and well known: big flies catch big fish. There's also a rush that comes with streamer fishing that doesn't come with other brands of fly fishing. Streamer fishing is distinctly different than dry fly fishing and nymphing and in most respects is more dynamic and varied terrain. Unlike these other tactics where following a few basic rules can lead to consistent success, the streamer fisherman needs to approach the water with a more predatory, evaluative eye in order to produce results.
Streamer fishing is about the world of swimming prey. Whether that prey is smaller trout, baitfish such as minnows, sculpins, leeches or something else entirely -- it swims. And imitating a swimming creature requires a different skill set and approach than imitating a drifting or floating one. Beginner streamer anglers will often try to apply the rules of the dry fly and nymphing worlds to that of the streamer fishing world and end up frustrated when the results don't come.