This activity features two seemingly identical black rubber balls—one happy and one sad—that behave quite differently. The two balls can be used to introduce the National Science Education Standards’ unifying concepts and processes and to raise questions about student diversity and teachers’ ethical responsibilities to care for and help all students learn, both despite past failures and beyond any past successes. The learning environment must be designed to help all students achieve full potentials rather than merely serve the few students who can adapt to a one-size-fits-all approach.