Living beneath my means is something I learned from my parents. They had 5 kids plus my elder sister who was still-born. Because my parents had to raise 5 kids they could not spend up all of their money on whatever they wanted because they had responsibility.
Therefore, they’d save money by spending less. Living beneath our means doesn’t necessarily mean doing without. It just means getting what we need at the most economical price so there will be some left over for emergencies or just to have if we want to use it for something.
My parents lived beneath their means by shopping at the thrift store for our clothing and toys as we were consistently growing children. My mom would also call around and get vouchers for some of the various thrift stores where we’d be able to pick out three outfits for free.