Can you ever be too ambitious?

Being ambitious is a good thing. For my opinion, I think that people can be successful only if they are ambitious. However, people sometimes fail because they are TOO ambitious. Many people get too ambitious because they are too proud or too confident. They don't know themselves well, don't know their real ability, and don't know what they are going to face, so they get too ambitious and fail. However, I don't think that I will ever be too ambitious. To be ambitious, I need to have a goal, to have something that we really want to do. However, although I have dreams that I want to achieve, I never set my goal so high that I can never achieve. I know my ability, I know how well or bad I can do, so I really don't think I will ever get too ambitious. Moreover, I am not a person that is ambitious. Although being successful is a good thing and a good dream, it is not what I most want. What I most want is a peace and normal life.