I remember being shown on the clock where the hands had to point before we were allowed to get up (before I could tell the time!), and dashing downstairs to see 'if he'd been'! The excitement of opening presents, then going to my Mum's parents' for more presents and a big Christmas Dinner that Mum and Grandma (and Great-Grandma, when she was alive) cooked while Dad and Grandad went 'for a pint' - they used to bring a jug of beer back for the cooks!
After dinner, we'd have to pack everything up and go to my Dad's parents' for tea. That was a whole different atmosphere - Mum's parents liked noise and loved making Christmas very special for us children (Grandad loved decorations and really went overboard - their house was like a grotto!), but Dad's parents were much quieter (his Mum, especially - devout Methodist). We'd have to play quietly while the adults sat round the room trying to think of something uncontroversial to talk about. Tea was always tinned luncheon meat and salad, buffet-style, and at some point in the evening the one allowed drink would appear (with the beer/larger drinkers sharing a can between two!). I think Mum and Dad secretly liked being able to use 'tired children' as an excuse to leave by about 7pm.
Despite the awkwardness of the afternoons at Dad's parents', they were happy days. We tried very hard to reproduce those happy memories for our daugthter and I think it worked - at 23, her idea of a perfect Christmas is getting up to find a small pile of presents to open (hopefully including some Lego and a selection box!), breakfast in her pyjamas and a big Christmas Dinner cooked by me. Nothing fancy, nothing expensive - just quality family time.