By these "business" words, did he mean trade(work-related things in a company) or a general responsibility that can happen in your daily life such as "none of your businees!" ? The word "business" can have lots of meanings, and in this context it seems more like work-related things, but I just want to verify it.
ex) Psychologists would probably tell me that I am a prime candidate for burnout. People say that I work too hard and too long under extremely stressful conditions. Yet I have never experienced anything close to what must be a terrible psychological state. One of the secrets is that I schedule time for exercise and rest and I am sure to observe to observe those time commitments. I also divide up my business emotions, which means that an emotion from a business situation doesn't influence another business situation. Last but not least, I write everything down, and put my notes where they will pop up again in the right place at the right time. The end result is that when I break from work I break from work-related stress as well.
Yes, work-related things. If he's having difficulty with client X, he doesn't let that affect his work with client Y. (Or project X and Y, or employee X and Y, whatever.)
I agree- it's work.