I've been decorating cakes since I was about 3 years old. Of course, at 2, my idea of "decorating" was "putting every single thing I could find on the top of the cake". My mum would ice the Christmas cake in glorious thick royal icing piled up like drifts of snow, and I (and my sister, when she came along) would populate this winter wonderland with a host of plastic Santas, reindeer, trees, trains, fairies. I don't remember ever actually including the animals from the toy farm, which included a walrus and a panda (we never wanted to be constrained by categories), but I'm sure it was only due to lack of space.
The cakes my mum made for our birthdays were more coherent, and endlessly inventive: a clock striking 'one' (with three blind mice running down it) for my first birthday; beautifully reproduced cartoon characters (Snoopy, My Little Pony, several years of Care Bears); woodland creatures, fairies, maypole dancers; cakes in the shape of upright pianos, computers, beds, books... whatever was central to our lives at the time.