In 1943 Karl Terzaghi published his famous book “Theoretical Soil Mechanics”, with only 7 pages dedicated to piles. Today, 80 years later, thousands of research papers and textbooks are proof of significant advances made in this field (new pile types, experimental full-scale observations, different method of analysis and design in a wide variety of soil conditions as encountered in practice, taking proper account for general loading conditions, etc.). In the keynote paper, a tentative is made to “distill” this broad literature, trying to pull out some fundamental aspects aimed to establish that undeniable expertise for any professional involved in piling problems.