The problem with being an inventive person is not having too few ideas, but too many. It's like being a radar operator on a plane constantly circling back through your own chaff. The ideas that you want to start, see through, and finish are constantly drown out with the calls of new ideas, abandoned ideas needing attention, and the concerns of normal life.
Most minds start out inventive, although all minds also start out being terrible at it. If you doubt this, get a four year old to tell you about their favorite subject. You will soon be up to your kneecaps in adorably terrible ideas. All processes need to be refined and learned. Unfortunately, many of us abandon our inventive spark and let the voices of day jobs and distractions of modern entertainment drag us into being walk-on characters in other people's plays.
This section is the first few chapters of a book I'm creating for inventors. I want to start a generation of a million mini-Musks, or people who awaken their inner inventor. Maybe it will be a billion-dollar journey or simply a far more interesting hobby than watching games and fictions.
The origin point of invention is the mind itself, and the conceptual framework of creating things in the real world from ideas formed after observation and classification. This is easier than it sounds. You do it anyway, frankly, otherwise you couldn't speak. Creating words and creating inventions are similar mental functions. You simply need to learn the language of how to turn observation and rumination into invention.