Call it learn....call it skittish...I would say that trout get better at "discerning" a "natural profile"....and more importantly a "natural drift" when fished over daily. They don't take to being lined, and they spot drag in an instant.

My question is....for how long? I would say that if those same trout were rested for 2-3 months they would resort back to slamming rubber legs and foam with a quickness. You get "flicked" in the ear enough times, you learn to spot it a mile away....but don't get flicked in the ear for a week?....and the next one takes you by total suprise all over again. And we have a brain to reason with.