Entrepreneurs are architects. We design, and in principle, get others to do the building. If you are working more than 40 hours a week, the chances are, you are doing the design work and the building work as well as many other tasks. This is not healthy. Being constantly attached to your phone is not healthy, and it's not necessary.
I do wonder whether the general perception of teachers in this country is informed largely by three main sources: Grange Hill, Teachers and Waterloo Road. It would be a real shame, when the profession has moved on from elbow patches and smoking behind the bikesheds whilst discussing a workplace romance, to see that undone by the constant barrage of generalisation about the way teachers perform.