Can a Manager Be a Successful Entrepreneur?

Of course, it just requires a different skill set.

Managers tend to be good at overseeing others and not necessarily being successful at any one valuable skill (sales and or marketing) which will be needed to start a successful business. The fact is you will need to get out from behind your desk and take a risk (with your own money) and be a leader that has to earn that position. Managers are appointed Leaders in a startup have to earn it.