I think anytime the brain is messed with, including surgeries insertion of foreign objects, etc., I think you injure a little part of the brain and the more you have the more damage is done. I am convinced I have learning disabilities because of hydro and the many shunt revisions I have had. Sometimes I feel angry that no one caught on to my LDs. But inspite of it, I graduated college with 2 degrees. I totally get the foggy-headed feeling and the feeling like I just am not as smart as others. But I try hard to focus on what I can do and what I have accomplished. Still though, it's hard not to feel bitter. I totally get what you are feeling.