I also have had the experience that some colleagues had worked on optimizing an algorithm for months and months. I too had looked at the algorithm and one day, almost out of the blue, I came up with a short cut that totally avoided said algorithm and implemented the required functionality with some calls to a function in standard library we were already using. Again, I was met with disbelieve when I presented the solution.
I feel that I am the guy who about once per year comes up with an idea that no one else had thought about and that most of the time I am just not very productive and often find myself daydreaming and not being very productive.
I also feel that often I am far ahead of other with respect to ideas and that I fail to convince others about a my '(too) advanced' approach. I several times have been in the situation that I proposed a solution to a problem and that some kind of manager decided to go for a simpler solution and that after months of develop time, it came to be that certain functionality did not work and that it was simply decided that that functionality was not going to be supported anymore.