why you wear your socks over your trackies

My georgeous little 4yo daughter came outside the yesterday wearing her socks pulled up over her trackies...

Can you think of a reason why?

I know I struggled with the idea, it looks rather daggy, although credit that they are colour co-ordinated!

Its so that you dont get sand in your pants when your playing in the sandpit!

Ahh- then great tips you learn from your kids!