Forgot The Milk Again

So I was at the grocery store today and my mind was just all over the place. I'm working on this big thesis paper, you know, trying to make sense of it all but only ending up with more questions. And then there's my roommate, she keeps asking me about this book club meeting we were supposed to go to yesterday, but really? I missed it because I was stuck in a lab until late and completely forgot. Anyway, today I go into the store with a list as long as my arm, every single item checked off except for one thing: milk. But when I got home, there's still milk in the fridge! My roommate had bought some yesterday when she went to that book club meeting without me. So I'm just standing there thinking about whether or not it matters if I tell her. I mean, I don't want her to think less of me for forgetting one thing on a grocery list, right? Or is it okay because everyone forgets things sometimes? And what's the point in admitting now when she already knows and bought more? Guess I'll just stick with my story that I was running late coming home from school and missed you in the aisle. It's silly, but these little things can really get under my skin.