Years ago, when I had a kindergartner and a toddler, I had a Tuesday routine. I took the toddler to gymnastics, then we went to the grocery store, then we picked up the kindergartner. I was so regular with this routine that if I missed a Tuesday, the grocery store clerks were concerned about me. Then life intervened, kids got older, and I did my grocery shopping on a catch as catch can (or can't) basis - which made me nuts but was the best I seemed able to do.
Life has changed yet again, and now I have a child at an activity for 45 minutes near the grocery store, at a time when I can haul groceries - on a Tuesday. So I am once again buying groceries on Tuesdays, whether or not we are desperate for them. It is lovely. When I put things on the grocery list, I know when I will get them, and we run out of things less often; I can mail packages or drop off film then, so I am more likely to remember them; I can check my post office box. But best of all, it reclaims a rhythm that I had really liked, brings a calm back into my life that the haphazard patterns had eliminated. It's funny how such small things can make such a big difference in your life.