I'm not going to use a shopping cart, because like I said, I get off the bus from work, go to the store and go home from there. I'm not going to carry around a Loblaws or Dominion bag just in case, I'm not going to get in a car to do groceries (a car truck is where it might make sense to store reusable bags), and I reuse the bags I get.
Grocery bag taxes and bagless stores are almost pointless in the grand scheme of things, especially as I have trouble finding Ontario fruit, even in season (so much trucked in from California, even peaches, which were just in season and so good from Niagara), food stuffs are so overpackaged (though since I buy most of my groceries in the perimeter, avoiding prepared foods for the most part, I don't do too bad), and so much energy is wasted by people driving to big box stores in sprawlholes that pretend to be environmentally friendly by going bagless.