Building on structures of unified time scale, causal manifolds, boundary time geometry, and self-referential scattering networks, this paper provides a mathematicized version of the traditional proposition ``my mind is the universe''. The core insight is: in a fixed-point universe with causal partial order, unified time scale, and generalized entropy as ontology, ``my mind'' can be formalized as observer structure organizing information, constructing models, and performing updates along a worldl