About 12 years ago, I lived on £150 a month for food, clothes, travel, to work, going out and anything unexpected. It went on for a year until I got a bit of a pay rise and mortgage rates fell.
There was only me and the cat at the time but it was a struggle. The cat became ill and I could not pay the £400 vet bill. My parents paid it for me fortunately- cat insured after that! I would have sold stuff to pay it if they had not helped.
I remember getting up really early and walking 3 miles to work to save £1.25 a day which totted up to about £6 a week and £24 a month- worth having to spend on something else. Once sold stuff at a car boot and made £200+ and it felt like a fortune.
I had no extras at all. I rarely went out socially - months could pass- did not have a drink, heating hardly on, made lots of soup, didn't have a holiday at all.
But I never once went overdrawn. It became a way of life to be careful.
Things got better and I got promoted, eventually met DH and we both have good jobs and are very comfortably off now but I haven't forgotten it, ever.