Ever go food shopping and think you need only a few items?
You do your shopping, thinking you didn’t buy much and then you get to the register.
The amounts on the register screen start piling up.
When your order total pops up you do a triple take saying “what?!?”
You’ve just spent way more than you wanted. What’s worse is you get home and you don’t really have much food for meals. Ends up you have a lot of snacks and such.