My mother was always the same way; she'd ask me to do 10 things and I'd do 9 of them before she came back to check, and instead of focusing on the overwhelming majority that I had done as asked she'd have a fit about the one thing I had not done. It was like that all my life - got a B on a test? Why not an A? Got the A? Should have been an A+. Got 100%? There was extra credit, why wasn't it the full 110%? And on and on and on.
At the time I couldn't escape her, but now that I have and I have a lot more freedom I've just let her go from my life. There's no room for people who make you feel bad about yourself, especially those who will only focus on the negatives like that!