This paper defines introspection as the emergent layer (13DD and above) conducting a structural inspection of the working interval (5DD–12DD), with the foundation layer (4DD and below) as its impenetrable boundary. Working within the Self-as-an-End (SAE) Dimensional Degree framework, it identifies four domain-specific findings: the structural impossibility of external measurement, the 4DD boundary (characterized through near-death experience and deep anesthesia), inter-layer barrier thickness (the thin line between genius and madness), and the mapping of Birth–Stabilization–Development–Fixation onto DD layers. The paper establishes the bidirectional colonization-nurturance structure between emergent and foundation layers, engages in dialogue with Freud, Jung, Husserl, Wittgenstein, Wang Yangming, Zhuangzi, Dōgen, Patañjali, Śaṅkara, the Heisenberg uncertainty principle, embodied cognition, and electronic music practice, and advances six non-trivial predictions with falsification conditions. Bilingual edition (Chinese and English). Keywords: introspection, Self-as-an-End, Dimensional Degree, expressive drive, Life Cycle Table, subject condition, colonization, nurturance, remainder Language: Multilingual (Chinese, English) License: Creative Commons Attribution 4.0 International (CC BY 4.0) Related identifiers: Is supplement to: 10.5281/zenodo.18727327 (The Complete Self-as-an-End Framework) Is supplement to: 10.5281/zenodo.18842450 (SAE Methodological Overview) Communities: (your existing SAE community if applicable)