What does it mean to be creative?
You could watch the most non-creative, linear-thinking, do-it-by-the-book cop work to solve a crime and you'd be amazed at how creative her solutions seem to be. Creative for you, because you've never been in that territory before, it's all new, it's all at the edges. Boring for her, because it's the same thing she does every time. It's not creative at all.
For me, creativity is the stuff you do at the edges. But the edges are different for everyone, and the edges change over time. If you visualize the territory you work in as an old Boston Bruins sweatshirt, realize that over time, it stretches out, it gets looser, the edges move away. Stuff that would have been creative last year isn't creative at all today, because it's not near the edges any more.
This gives you two useful tactics for problem solving:
1. If you want to be creative, understand that you'll need to get to the edges, even if the edges have moved. Being creative means immediately going to the place the last person left off.
2. If you are "not creative," if you are the sort of person that gets uncomfortable being creative or has been persuaded you're not capable, don't worry about it. Just stretch the sweatshirt in your spare time, watch the creative things other people have done, keep up with the state of the art. Then, when you do your "not creative" thing, most people will think it's pretty creative indeed.