They don't deal with things until necessary. Once you learn to wait, you can stop an emotional response while you examine it. This is emotion vs. objectivity. I you don't wait, you will continue to be emotional, and will have difficulty separating emotion from objectivity. It's facts vs. feelings.
Objectivity is required to serve goal-directed behavior.
Perspicacity is the kindling of motivation. Motivation is an emotion. The normal attitude with an unpleasant task is that you 'stick with it', as there is a reward at the end. In ADD, the reward must be in the task itself, not after it. Most children can kindle motivation, the ADD child has to find it in what he is doing at the time - he has trouble kindling motivation to do an unpleasant task.