A buddy of mine who happens to have the Apple Watch and can now make contactless payments (see I.T article
http://www.irishtimes.com/business/technology/apple-pay-contactless-service-launches-in-ireland-1.3000151) in whichever stores supports it has been, naturally, extoling the virtues of such a system. Not having to carry a wallet when he goes out is one of those perks and secondary to that he doens't need to sweat about being put into a position where he can only get 50's from the ATM and needs urgently to pay for a bottle of water, just to pick an example. In most shops this is no big deal. I know it's a different situation in taxis etc, where the float is normally relatively small.
He argues that once a 20 or 50 euro note gets 'broken' the rest of the change just vanishes into the ether soon afterwards. I would contest that the units of cash are just in smaller, more discrete units - 5s, 10s and 20s and whatever else in terms of coins. It's still up to the individual to manage their money after getting their change back from the cashier.
If anything, I would argue that when you have tangible money in your wallet you can more easily plan your day-to-day budget. Electronic/contactless payments may lead to more frivilous spending, but again, that all rests on the individual.
Do you think that those who get into a panic at 'breaking a note' have an actual rationale?