Hi, Dawn! That's a great quote, isn't it?
While I'm not able to access the Disney Parks internal point-of-sales merchandise system to absolutely track this sweatshirt down, I'm going to provide four separate but equally great answers of where you might find the item in question:
First up: In
Magic Kingdom Park I would try "Disney Clothiers" or the "Emporium" shop, both on Main Street, U.S.A. (If you're looking at Cinderella Castle, both will be on your left.)
Secondly, download the
'Shop Disney Parks' app to your smartphone, which does have access to that fancy system, and can even provide a map to shops that do have your sweatshirt in stock.
Third, if you're already home, is the 'Parks' section of
ShopDisney.Com, which is where you can find an assortment of items that you saw on your most recent trip to most Disney Parks destinations that you couldn't find in your size while there or thought that you'd see at another shop later on. (OR didn't decide that you wanted until you were home, weeks later, like what I usually do.) Scroll down a bit and select "Clothes" in the "Shop by Category" section. That will take you to a new page where you can filter your search to just sweatshirts and jackets.
And Lastly, you can always contact 'Disney Parks and Resorts Merchandise Guest Services' at 877-560-6477 or by emailing Merchandise.Guest.Services@DisneyParks.com (Please note that shipping and handling fees do apply for this service.)
I hope you find your sweatshirt, Dawn, and that you remember your favorite vacation every time you wear it!
~Kristen