One issue to keep in mind is that things look obvious after you've been thinking about that thing for weeks, or months, or possibly years. Then when you have a proof, you think about how to present it, and how to generalize the idea in question. After all of that, the basic direction will seem more obvious to you than to someone who hasn't thought about it that much, since you've gone down the same mental paths many times. This also has a consequence in teaching; if there's disconnect for research, it may be even stronger when one is dealing with things one considers basic or obvious because you've used them since you were young.