They have to be worked frequently in order to stay sharp. Other dogs learn quickly and never forget. Airedales are like that. She is too smart to be worked every day. She gets bored with the repetition.
Many trainers see distractability as a sign of lack of intelligence.
In fact, distractability is often a sign of very high intelligence. They lose focus, daydream, fidget, etc. The same is true in dogs. If your dog learns quickly, repeating the same thing over and over and over will cause the dog to lose interest and the dog will be easily distracted. In addition, some dogs are bred to be leaders and some to be followers.