  With discovery of the Higgs boson, science has located the source for
$\lesssim 2$% of the mass of visible matter. The focus of attention can now
shift to the search for the origin of the remaining $\gtrsim 98$%. The
instruments at work here must be capable of simultaneously generating the 1 GeV
mass-scale associated with the nucleon and ensuring that this mass-scale is
completely hidden in the chiral-limit pion. This hunt for an understanding of
the emergence of hadronic mass (EHM) has actually been underway for many years.
What is changing are the impacts of QCD-related theory, through the elucidation
of clear signals for EHM in hadron observables, and the ability of modern and
planned experimental facilities to access these observables. These developments
are exemplified in a discussion of the evolving understanding of pion and kaon
parton distributions.
