It's not a glamorous job. The pay's rubbish and you end up with Repetitive Strain Injury. Sometimes they call you 'buddy' or 'blood', sometimes they treat you as an inconvenience. But it's a job, and they're hard to find these days.
So please refuse to use the automated checkout machines. Apart from the fact that they rarely work properly, they're not 'efficient' for you, but for the company. They're explicitly designed to take jobs away.
Or rather, they're explicitly designed to move jobs, from someone paid a pittance to someone not paid at all: YOU. What automated machines do is transfer labour value from them to you. Unpaid, you do what a till operator once did. Under the guise of convenience, they've found a way to persuade you to do someone else's work.
In a sense, you're actually paying extra to do it: the price of the goods remain the same whether you go to a staffed till or use the automated system. This means that the profit margin has increased by the amount an operator would have been paid to serve you.
I hate it when workers encourage me to use the self-checkout. I look embarrassed and politely decline. If they carry on, I explain that it's a ruse to replace them. They either don't believe me or look worried that management might overhear this tiny act of subversion. It's not nice - but please do the same.
Oh, and Boots? They've discovered a neat line in sarcasm - when I went in for medication yesterday (overactive sarcasm gland), they were playing the tuneful folk ditties of notorious anarcho-crusty band The Levellers. Now that's appropriation, folks!