I have been a Harry Potter fan since the 2nd grade. However, as I have grown, the characters have become more complex as my cognitive complexity has become more sophisticated. As a child, Snape was simply pure evil to me. However, as the series progressed, and I got older, I came to see that the distinction between good and evil had a lot of grey area, and I came to respect the good in Snape, despite shades of evil in his life. My personal constructs have become more nuanced.
I still pride myself in the fact that from the completion of reading the first Harry Potter book when I was in elementary school I decided that Snape really was a good person. I wouldn't learn for years later that he actually was. I always liked Snape. :)