The word Squander means to waste (something, especially money or time) in a reckless and foolish manner. Most people do not like to think of themselves as squanders of wealth. But if you are living paycheck to paycheck with no savings. You are a squanderer of wealth. Allah says ...
"And render to the kindred their due rights, as (also) to those in want, and to the wayfarer: But squander not (your wealth) in the manner of a spendthrift." [ Quran 17:26 ]
A spendthrift is a person who spends money in an extravagant, irresponsible way. These are the same people....talking about you, who have money for McDonalds or you have money for shopping for clothes, you eat out every other week, you go to movies, you go partying on the weekends, etc......but you say you don't have money but you have money to do what you want to do. You are a squander of wealth. Allah is talking about you, where he states : "squander not (your wealth) in the manner of a spendthrift."
I already know what you are saying and Yes, you are right, we only live once. But you may live to a very old age. People are living longer now a days due to improvements in healthcare and medicine. Are you looking to the future? Are you ready for retirement? Besides your family has rights too. You must leave a legacy for them when you are gone. But if you squandered your wealth you may not be able to care for yourself in your old age, and your kids may have to start all over again from scratch. Each generation should be doing better than their parents not the other way around.
When you buy things you do not need, soon you will have to sell things you have to get what you need. So, therefore, you can't be wasteful. You can't squander things, or you jeopardize other people in the process. You should have money put up for a rainy day. You should put away 10% of your income, treat it like your rent or mortgage. Have multiple sources of income. Don't be so reliant on your income. You can get laid off or get injured. Save some money, invest part of your income. Flip your money. It's our responsibility to pass on what we have earned in this life, not to squander it, but to build on it. And have some left over to..."render to the kindred their due rights, as (also) to those in want, and to the wayfarer".
On the day of judgement you will be asked what you did with the wealth you were charged with, however small or large. You don't want to go before your Lord saying I spent it on Red Bottom Shoes, on Jordan Sneakers. Our wealth was given to us by God-Allah, and he wants you to help others and make the earth a better place. Not just for shopping, and eating out. So we need to be good stewards over it. Having money will give you the power to do good in the world. I hope this was helpful to you as it was for me. Love you family. As-Salaamu alaikum!