I think it's more complicated than just the term, "mental toughness." I like the idea of toughness, but I don't think it is an accurate descriptor and I wish we would call it something else. When we are thinking about things that are hard, the reality is the most hard thing is other people telling you that you are wrong. Something can be hard, but if you have the right mindset and the right people in your corner it feels doable. If you are dealing with a client that is blaming something highly emotionally charged like their pet dying on you, or you are dealing with another vet telling you you did something wrong, it is harder to be mentally tough. And for me, dealing with those things takes tools that we don't all learn, such as being confident in our decisions, and being okay if we made a mistake. If I had to pick one thing to focus on, it would be that. Heck, we are all taught that being humble is better and that we should be ashamed to stand up for ourselves. It is not as easy as building a muscle, it takes unlearning lessons that we are taught by our society and building habits that are actually healthy but we are taught are impolite. Persistence, adaptability, confidence, and the ability to change our minds when presented with new information instead of latching on to old ideas - these are the skills I associate with mental toughness that I wish we were all comfortable with. I am not sure if this is what you were looking for but it is what comes to mind for me.