Forgot The Milk Again

So uh, today I was supposed to go to the store for my wife and get milk. She asked me multiple times during our morning routine about it, you know how she reminds me? 'Hey honey, did you remember the milk?' So yeah, at first I said I'd totally gotten it, but then halfway through the day I realized I didn't actually do it. But by that time, there was no way I could get to the store without her knowing because we both had things to do. And so I got this strange sense of guilt all day long. 'Oh man,' I thought a few times while walking around our kitchen that afternoon, 'she's going to find out eventually.' It wasn't until late evening when she casually mentioned again, with a bit of the concern in her voice, that my cheeks started burning. I mean, it’s not like milk is such a big deal really, but it feels silly to lie about something so small, right? And now we're running low and I can see why she's starting to get annoyed. This kind of thing happens too much for me to feel good about it...