my former pet (passed away last year), he got like that with younger children as he aged. He wasn't agressive with everyone. The vet suggested due to his aging he was getting tempermental and seemed not to like louder noise and more agressive child...

I have heard conflicting things about separating a puppy from it's mother before 8 weeks. What is the problem, or what can go wrong if you take the puppy at 6 weeks instead of 8 weeks? Any thoughts?