This lecture covers the fundamentals of turbulence theory, including the three hypotheses of restored symmetries, self-similar scaling, and finite dissipation. It delves into the challenges of intermittency corrections, universality of decay, transition to turbulence, and smoothness of Navier-Stokes solutions. The presentation also explores the Richardson cascade, energy transport, and the open questions surrounding turbulence, as famously stated by Feynman. The lecture concludes with a humorous analogy of turbulence research as an alpine expedition to the challenging 'Pic de Navier-Stokes'.