There is something quite comforting in wearing three-size-too-big boots. Bigger steps, exaggerated, take you place to place, and in order to run, you must high-step it, giggling all the way.
I think that it must be because of all the times you wore your father's boots when you were little, that you so cherish it now. The times when you slipped into the cavernous boots to drag your feet, creating a muddy trail through the snow to the mailbox, the old metal box echoing your hands' request for mail.
I think it must be because it reminds you how to be little again, it reminds you that you aren't all that grown-up, it helps you feel better, since you're already taller than your mother, and the feeling of tucking your head under her chin, just isn't there any more. It is better to know that you are still little, that your feet can still jostle around in too-big boots, even if you can reach things your mother cannot.
So I'm glad you have these boots, because I like to see you laugh, stomping through the snow, shuffling around, and giggling. I think that it is good for you. And I hope you have a nice day.