I still don't see why the act of not carrying cash is irresponsible. Inconvenient at times, sure. But irresponsible? I mean there are instances where I can't use a CC (terminals down, cash only, etc) but I've just gone without making a purchase. No big deal. Losing my wallet the second time with quite a bit of money in it was the reason I stopped carrying cash, but not having cash also helped me stop using vending machines. There are lots of good reasons to carry cash, and many good reasons why it's not necessary, but I wouldn't say the act of not having cash is irresponsible.