Experimental signatures of multi-particle collectivity persist for a broad variety of system sizes and interacting probes, such as in low-multiplicity proton-proton collisions and for charm quarks in proton-lead collisions. This behavior seems to be so ubiquitous, that it is almost as interesting to observe when a probe does not participate in the collective motion in a given system, as when it does. In this seminar, I will highlight some of our work in trying to delineate the boundaries of where collective phenomena start and stop using the ATLAS experiment at the LHC. Finding these boundaries can help better reveal the underlying dynamics of the many-body QCD systems produced in these collisions. I will discuss results on measurements of collectivity for charm- and bottom-separated heavy quarks in pp collisions, for very high-pT particles in p+Pb collisions, and in ultra-peripheral photo-nuclear collisions selected during Pb+Pb data-taking.