Trout have long been considered smarter than the average fish. Simply because they have the same instinct to run for cover when they hear or see the slightest vibration.
The main thing that distinguishes trout from many other game fish is the pretty setting that they live in and the fact that they like colder water than most fish. (50°-65° F). This fact means they live in water that is fed by springs, snow melted lakes\, or streams with a good current. Plus, the quicker the stream is moving, usually the less sediment falling to the bottom of the stream. This is good for trout because it offers no hiding space for live insects of the stream bed. A quick tip if you ever see a stream and you see it is made of limestone, try to fish it sometime. Limestone streams have more aquatic vegetation, which produces more insects. Generally growing larger trout!