"Memories?" Sai's brows knit together. That was particularly troubling, because if he'd had something like that taken from him, he might not even realize it. You can't miss what you've forgotten, after all, and he shared no childhood memories with Naruto and Sakura so they wouldn't be able to fill in the blanks for him. He didn't feel as though there were any blank spots that hadn't already been there before, but there was no way to tell for sure. "Was it any more than that?"

If he had to pick between losing memories and losing access to his chakra... well he would probably pick the latter. A ninja could learn to fight without chakra. This is not unheard of, even if it puts them at a great disadvantage. Memories, on the other hand, were something he cherished. If he ever forgot about Shin...

"I lost access to my chakra - the energy a ninja relies on for most of their techniques. At least, this appears to be the case." It could be something else that was causing this problem, but somehow he doubted it now.