No. I am not joking.
Reflections of what? A bad hair cut?
He has a short even haircut. The hairs tend to point out from his head. When certain kinds of camera flash go off near him, most of the light from the flash is caught by his hair, but at certain angles the flash bounces directly off his scalp towards the camera lens. The combination of his hair pattern and the direction of the light from the flash make the reflections appear to lie along lines. Conspiracy theorists like to interpret these reflective lines as scars.
You can tell that these lines are reflections and not scars in the following ways:
1. Can you find a single instance of anyone who has ever met or seen Obama in person and has said anything about seeing scars all over his head? Of course he has probably met or been close to hundreds of thousands of people.
2. Dig up multiple pictures that are supposed to show the scars. Do they even agree on what side of his head the scars are on or where they are located? Do any of the pictures have enough resolution to show that the lines are scars and are not an optical illusion caused by the camera flash?
3. My explanation is logical. Your explanation just involves your imagination about surgery or a horrific accident that somehow magically missed his face and ears and has somehow been totally covered up.
Plastic surgery.
And as other scars seen on his neck similar to tumor removal also seen on the Internet.
Broken skull trauma does not lend itself to plastic manipulation/repair quite so easily but still possible to some extent.
Or simply black dye!!
Very strange pattern for reflected light!