The frustration mounted on my client’s face. Finally, the words burst out: “I’ve owned them for two years. I’ve taken lessons. I read everything. When am I going to know everything I need to know about horses?” she said.

The laughter got past my filter. “I’ve worked with horses since I was 19,” I told her. “I have a bachelor’s degree in animal science. I’ve been a veterinarian since 1996. I’ll let you know.”

As she began to grin, I added, “Any good horseman or woman will tell you that they learn something new about horses every day. Honestly, I think that the longer I’m around them, the less I think I know.”

The last lines of the veterinarian’s oath read: “I accept as a lifelong obligation the continual improvement of my professional knowledge and competence