My about to turn 5 yr. old has some difficulties as well. I do identify with your "he has to learn the hard way" statement.

Have you looked at books about sensory integration issues in children? Maybe an evaluation by an Occupational Therapist may help. Also, consider a Montessori-based environment and/or homeschooling to provide the structure he needs.

We're also eliminating dairy. Because we're combining that with other behavioral modifications, I can't say that it's helped, but I do notice that his asthma has been triggered much less.