Why does Father Christmas go down the chimney ?

I think it is because he expects everyone to be in bed an asleep thats why know one see's him. Because he doesn't want to knock at everyones door an wake them all up an ruin what is a big surprise for everyone. Plus it would slow him down to talk to everyone it also means he doesn.t have to explain why some people did not get anything, besides they should know already if they have been or nice. Happy Christmas HO HO HO!