The Grocery Store curse...

Why is it that I always forget at least one item at the grocery store? I'm an obsessive list maker, I write it down, then I recopy it about three times, making my writing all pretty and putting my list in aisle order of the store {yes, I memorized it - I could draw you a map of my SuperTarget from memory} - if I make a mistake I start over - then I go & I shop & I feel good about everything. Then I get home and start putting things away...let the swearing begin...never fails. I consult the list - and there it is in my pretty handwriting - my confession: once I'm shopping I rarely look at my pretty list. What's that about? Not only do I need therapy, I also need a package of large flour tortillas and green chile enchilada sauce...