I love career brainstorming. I love how people dream up new ideas for jobs and careers, how they see paths they didn't see before, how they see old ideas in new ways. When I speak on careers or run brainstorming events, seeing what people dream up is amazing and enthralling.
You probably know what it's like to brainstorm for yourself as well – the research, the dreaming up new businesses and new places to work, coming up with new things to do. However you're also likely to restrain yourself a bit, hold back, look for quality ideas so as not to waste your time.