I found out last year that a girl I knew back in high school and went to my church had died just the year before in '06 of cancer. She and I used to argue quite a bit through grade school, and we had a bit of a somewhat friendly rivalry -- she used to tease me mercilessly, and I did the same back to her. Other than that there was no ill will between us, if not outright friendship.
I spoke with her younger sister in August about her death (ovarian cancer), apologizing for having lost contact with them so long ago. She told me that her sister, the "pest" as I had called her, who had married and had a family of her own, had carried a bit of a torch for me then and for a lot of years thereafter. I never knew -- it shocked me to my very core.
So, yes, it is certainly possible. Surprisingly to me.
