If you're an entrepreneur, you should never be satisfied with just one product or service idea to develop. A list of several dozen potential money makers is much more efficient. I have seen many would-be inventors stop searching after their very first idea. After pouring their life savings into a their new mouse trap, just to find out that nobody has mice, they seldom made another attempt with a new concept. A better approach is to have lots of ideas and have the courage to quickly abandon one dead-end concept in favor of another more promising one.
Some people have a real passion for new ideas.
Instead of collecting coins, stamps, beer cans or computer games they tend to collect ideas. I fit into such a category. I love science and engineering and I spend much of my spare time reading about it. Every new technology that is announced produces a whole series of new invention ideas for my list. I'll toy with the idea until I'm satisfied with its potential or limitations.