Yes Hally it is sad when they stop believing
Hally my DS is almost 13 and I've never heard him say anything about there being no Santa, I'm sure he knows but it's something that is never discussed in our house. Our DD who is 17 gets into the spirit even more than I do and would never think to mention it's not real although she does ask me for specific things for christmas.
I also think food at Christmas used to be more special, now we eat it all year round, I think as the kids get older it is not as exciting