My cats both suffer from Attention Deficit Disorder (ADD), to varying degrees. This is not the same as human ADD, although cats are even more easily distracted, and not meant as a slight to those who suffer from ADD in its many forms (we have friends who struggle with this, and it is a struggle).
But it occured to me yesterday that Sheba showed definite signs. While I was eating my breakfast, she hopped onto my lap. Repeatedly. Not content to just sit in my lap, she had to be rubbing herself against me, including rubbing her head on my chin. You might imagine that this interefered with my breakfast a smidge. After she finally got tired of me removing her from my lap, she turned her attention to John and Rachel. First one lap, then the other, then, eventually, she lay down on BOTH their laps - at the same time. Clearly she was hoping for loving from both ends (John wasn't so obliging).
Given that this is not unusual behavior for her, in fact, at the moment it's unusual that she's NOT on my lap or in my face, I diagnosed ADD. Clearly, she feels there's a deficit in the attention that is paid to her.
George has it too, but he's a little more polite about it. Usually.