We have them all the time. We'll just be sitting and doing our thing, which may be reading, blogging, surfing the inet, crafting, whatever. Then it hits you. Random thought which has nothing to do with what you're doing. I crochet all the time and think about things totally unrelated to crocheting. When is the husband going to get up? Is the cat hungry? Does the cat want out?
Of course, I also tend to think about the crochet at times too. "What else is this pattern good for? Can I make an afghan out of these squares? Can I make a potholder out of this stitch pattern? Of course then I have to try and see. I think I'm going to get a dish towel out of the double knit Hoover baby blanket. I cast on far fewer stitches than called for to practice the technique. It would make a good doll blanket as well, but I can use a dish towel/rag too. I'm also using acrylic, so it will do good for a scrubber.
While working on a diagonal potholder, the technique would also make a nice bag. Just put handles on it and make it taller. The squares I do would make good tote bags too, just sew them together and put in handles. Actually, the squares are small enough to make nearly anything out of. It's just sc around, make three in each corner, then cut and change color. Use two different colors. Kind of a sc Around the World. I think they're about four inches square, so pretty small. They may even make good slippers too. I'll have to make a dozen and put them together and see what they look like. It would be like the Granny Square Slippers that I've made plenty of. You just sew six squares together (or crochet them together). Put four together for the sole, one for the instep and one for the heel. Looks great and you can make them in any color combination. The problem with granny squares is the holes. So these sc squares might make an even more cozy slipper.
The thermal stitch would make a good thick sweater or wrap or even afghan. There's so much you can do with just one pattern that there is no way to make everything you think about. It's fun to think about it though. Of course, you would need much patience to make a thermal stitch blanket, unless you made it in squares. Row upon row, hundreds of thousands of nothing but sc. Hmmm, sounds like a chevron too.