  Atomic nuclei lie at the core of everything visible; and at the first level
of approximation, their atomic weights are simply the sum of the masses of all
the neutrons and protons (nucleons) they contain. Each nucleon has a mass $m_N
\approx 1\,{\rm GeV}\approx 2000$-times the electron mass. The Higgs boson --
discovered at the large hadron collider in 2012, a decade ago -- produces the
latter, but what generates the nucleon mass? This is a pivotal question. The
answer is widely supposed to lie within quantum chromodynamics (QCD), the
strong-interaction piece of the Standard Model. Yet, it is far from obvious. In
fact, removing Higgs-boson couplings into QCD, one arrives at a scale invariant
theory, which, classically, can't support any masses at all. This contribution
sketches forty years of developments in QCD, which suggest a solution to the
puzzle, and highlight some of the experiments that can validate the picture.
