Education is linked to (neuro) biological processes. Failure to observe provokes challenging behavior. The case studies deliberately assume extreme biological conditions: autism, trisomy 21, Tourette's syndrome, epilepsy, ... André Frank Zimpel shows that the key to sustainable success is to look at the inside of the apparent to approach failing children, adolescents or adults. For less restrictive learning difficulties, the following applies even more: biological limits are a challenge, but not an insurmountable obstacle.