Do you agree or disagree that it is only possible to have a successful career if it has been carefully planned?

I'd say planning helps, but success often comes from adapting too. In my work as a UI designer in Shanghai, projects rarely go exactly as planned - clients change requirements or new design trends emerge. What I've learned is that having a clear direction matters more than rigid planning. For example, when I first started, I carefully planned to specialize in mobile apps, but then our company got more web design projects. Instead of sticking to my original plan, I adapted and now I actually enjoy both. That being said, completely winging it without any planning would be stressful too - you need some structure to build on.