I can actually speak to this personally, since a credit score is just a rating that describes how safe it is to lend you money based on your past payment history. I had I think a 650ish credit score after two years and all I did was pay off my credit card every single month. It didn't actually matter that it was mostly just buying the odd coffee or meal. Even if you only have a balance of ~$50 on your card, paying it off each month is very good for you. As is not missing bills, not having multiple credit cards, not hitting your max balance etc. The redditors are just outing themselves as fiscally irresponsible.