Where do new ideas come from?

I think, new ideas come from personal experiences, things that happened during the time a person wrote a story or book, and if a person is creative, of course from his or her imagination. For example in "The Sniper" the civil war played a big role for the IRA sniper, but as well for Liam O'Flaherty because he was part of it once. An author or anybody else, also needs personal experience to write a story, novel, song, etc. because you can't for example write a love song, if you never have been in love before. The author has to know how a person feels and/or acts in a certain situation because only by knowing that, the author can get close and capture the audience or readers. But if there is nothing exciting happening while a person writes a story, or he/she already wrote about all of his/her personal experiences in life, authors can also make up stories. Of course not only authors need new ideas, also teachers or other people need ideas. For example if you need to design a catalog, you really need ideas too, because otherwise the catalog won't look good or the client is not happy with it. Everybody needs new ideas, and they can come from everywhere, but the three things I've listed, I think are the main sources where people get their new ideas from.