As a non-parent I do get this sentiment--certainly there can be many important things beyond children that call our time--however as someone who has dated someo

As a non-parent I do get this sentiment--certainly there can be many important things beyond children that call our time--however as someone who has dated someone with a kid and seen the kind of time and energy a child demands, OP's statement is spot on. It's more of a paradigm shift in the way you think about time -- you're suddenly not just responsible for yourself and your accompanying todos, but a whole nother human life, and their accompanying todos (which are manifold greater because they're dependent on you for even the simplest of needs).