My mum chose the cult when I was 3 or 4. There are photos of me as a baby by a Christmas tree but I have no memory of celebrating.
Christmas and Easter too were horrible times to be at school. Teachers were mean and hated the witness kids who would refuse to colour in a tree or an egg.
Having worked in a school I have seen and heard the experience from the other side. In my class we had a Hindu boy who was not allowed to celebrate either. The teacher made sure to make him suffer. Every day during the Easter period and Christmas period she would remind the class that he was not allowed to join in and shake her head and say how sad it was. These children were 5 year olds.
She made no effort to adjust her curriculum to him and seemed to take pleasure in torturing him. I told her that it wouldn't be hard to find worksheets for him to do that were not ",holiday" based and just to give them to him quietly so as not to make him feel even more isolated than he already was. She didn't do it of course but I hope it made her think about what she was doing to him. These children have no choice in the matter I felt so bad for him because I knew exactly what he was going through.
Even when still "in" I would let my kids go to the discos and end of year concerts and I would get all their friends a small gift and a blank card (not Christmas) that the kids could write them an end of year message and if they got Christmas cards I would let them keep them.
I can't see us celebrating Christmas as a family any time soon because to me it's so commercialized and it annoys me that they still insist on celebrating Jesus birthday in December when it is widely known to be a pagan celebration. I won't do it just because everyone else is doing it. But it is nice not to feel guilty about saying ", thank you and you too" when someone wishes you a merry Christmas.