I come across many ideas and many people who have many ideas. Ideas are cheap. Finding and applying talent and sustaining attention is not.
Ideas are seeds. A startup is a garden.
Ideas can come from anywhere, and often, a "new" idea is a relatively novel combination of existing ideas.
Having ideas and judging them as valuable insights can trigger a dopamine rush; the feeling of discovery. And it can be addictive.
However, ideas represent potential. Ideas are the "talk" in the saying "talk is cheap."
The human mind has the extraordinary capability at moving near the speed of light. Whereas, human hands currently have the humbling limitation of moving at... well, human speed.
And thus, it is easy to get carried away with ideas because the lack of friction provides an exploratory excitement. Whereas, the realistic execution of an idea is in most cases, not as exciting, repetitive work, mostly consisting of disciplined and dogged persistence in pursuit of development, creation, and delivery of the product or service to a customer who is willing to exchange value (pay) for that work.