Foundations; Why geometry, so physics, require complex numbers; Properties of state functions; The foundations of coherent superposition; geometry, transformations groups and observers; The Poincare group and its implications; The dimension of space; Bosons, fermions, spinors and orthogonal groups; The complete reasonableness of quantum mechanics; Terminology and conventions; The Einstein Podolsky Rosen paradox; Experimental meaning of the concept of identical particles; Nonexistence of superselection rules; Complex groups, quantum mechanics and the dimension and reality of space; The reality and dimension of space and the complexity of quantum mechanics.