Imagine a moral agent with the native capacity to act rightly in every kind of circumstance. She will never, that is, find herself thrust into conditions she isn't equipped to handle. Relationships turned tricky, evolving challenges of parenthood, or living in the midst of global pandemic-she is never mistaken about what must be done, nor does she lack the skills to do it.When we are thrust into a new kind of circumstance, by contrast, we often need time to practice discernment, new forms of compassion, different kinds of courage, or whatever else conditions call for. Whereas our imaginary agent has the native capacity to act rightly, we need to practice skills and habits appropriate to new circumstances. Unfortunately, practice usually takes the form of on-the-job training-it is hard to cultivate the skills of an excellent parent, for example, until we actually are parents.On-the-job training has an obvious drawback: mistakes are basically guaranteed. This paper focuses on errors that (a) cause harm to others, and that (b) we make non-culpably because our skills are (understandably) not yet up to snuff. What attitude should we take towards these significant-yet-non-culpable failures?According to much moral philosophy, non-culpable failures call for agent-regret. My aim is not to discredit agent-regret; it does serve an important moral function. Rather, my aim is to complicate a too-simple picture. If we take seriously our need to practice moral skills-such as discernment, new forms of compassion, different kinds of courage, or whatever else new conditions call for-we will have reason to cultivate an attitude I call stoic determination.§1 explains how we practice new moral skills. It focuses on Stohr (2019), which gives us a framework to understand the mechanics of moral practicing, and, thereby, to understand the predicament of an agent who does not yet have the skills or habits she needs. §2 is an extended interlude that illuminates the limitations of agentregret. Some kinds of non-culpable mistakes, §2 argues, call not for agent-regret, but an attitude I call stoic determination. §3 returns to the predicament of on-the-job