Being an entrepreneur has a direct impact on those closest to you. Working for a company brings many advantages and disadvantages, as you have job security (in theory) but not necessarily the freedoms that come with being your own boss. Entrepreneurship has a different impact, as work hours and security can be all over the map, while the freedoms you might expect are not always present in the early stages of starting your venture. The responsibilities and pressures of growing a business mean that your family has to be part of your work life or they may feel squeezed out during the times when you are focused on work issues.
Additionally, if you make the leap from employee to entrepreneur after you have a family, it might not be the lifestyle that your spouse and children expected. Being part of an entrepreneurial venture, even from the home-side of the fence, can be quite an experience.