Okay, when I was in primary school, my step dad had a drunken accident on a bicycle (dont ask) and sustained a serious head injury (not enough, again, dont ask). As a result, my mother insisted my sister and I had to have bicycle helmets at all time and proceeded to order us 'Stack Hats' (popular brand of bicycle helmets at the time in australia).
So how big is my head? Lets just say she had to order the largest in the range. I was just a little hurt by that, but oh well.
My eldest son has inherited my large head and has a high metabolism, so he looks like an orange on a toothpick. Said in the most lovingly way of course