Earlier quoted context omitted.
Small tangent: I tend to borrow all the money that is offered to me at 0% effective rate, e.g., when buying a new mobile phone. I would even go as far as to borrow all money that is offered to me at sub-inflation rates. Is this rational?
You just need to be careful because usually these offers have fine print along the lines "if you don't pay this back fast enough, you will have to pay very high interest even on the debt you already paid off."
Luckily I was able to get them to reverse it and then I just paid it off, but had I not noticed, I would have owed them a ridiculous amount of money.