When I was 17, my mum was invited to a teacher-parent meeting by my 'A' level Psychology teacher, in which she was told that they were worried about me being "too full of extremes". For every essay I had written in class I had achieved a very good grade, but apparently my arguments were too one-sided.
To put it more tactfully, I believe they had suggested that I "had very little grey" in my personality - I was either black or white in my opinions and never quite embraced the middle ground.
I always thought that my strong opinions showed strength of character, personality, beliefs etc. but hey ho. I'm slightly better nowadays, and even when there is an obvious correct side of the argument, I do at least try to see it from the other point of view.
I have recently taken the accusation that I lack grey, and I have defied it!
I'm a new grey convert, although admittedly that is only aesthetically rather than in my opinions, but at least it's something, right?