Probably things like living paycheck to paycheck. Needing a new washing machine or some other device but not being able to afford that yet. Not being able to have your car repaired or buy a car so you have to use public transport and walk long distances to get to your work.

I mean that's what I imagine. A little money would make those problems go away. But when your paycheck only covers your rent, bills and food, you never get to save up for things.