The standard approach to collective neutrino oscillations has been called into question because it does not account for entanglement. In response, we have proposed the "once-in-a-lifetime encounter” model, which aims to describe how neutrinos become entangled as they interact with each other. Such entanglement could occur in core-collapse supernovae and neutron star mergers, affecting the way they explode or merge and their role as the primary source of the universe’s heaviest elements. I will present the model and its predictions in some simple scenarios in which neutrinos interact with each other. If time permits, I will also talk about a parallel approach called “miscidynamics,” which describes how entanglement can adiabatically drive the evolution of interacting neutrinos.