For potential consideration by the Mind, Brain, and Education community, here is a modest but provocative hypothesis regarding the relationships between acquisition of languages, awareness of cultures, and development of ethics in human beings. Starting from the basic idea according to which "a fish does not know what water is," and using both various literature sources and my personal experience of linguistic/cultural diversity, I postulate, using the mathematical metaphor of the "tesseract," that mastery of several languages is not only essential to developing cultural awareness but also a key to (partial) access to global awareness. This might open research avenues for colleagues interested in some of these fields, or in all of them; if sound neuroscientific work, possibly combined with quantitative studies, proves the hypothesis right, then we may hope to take one small step toward more tolerance: yet another "giant leap for mankind"? Let us dream--it is not forbidden yet.