Living in a box

Whenever I get a delivery and there are any cardboard boxes Finn immediately says 'can I have the box?' - He has hours of fun, climbing in and out, making beds in it, driving his cars in and out, pretending it is a car, or bus, or plane or train, hiding in it and jumping out. You name it, that box can BE anything that he wants it to be.
There's something about a box, the confines of the box, thinking outside the box whilst inside the box. Letting your imagination run wild in the confined, cocoon like safety of your new abode; dark, solitary......almost womb like.