MickS has hit the nail on the head. Don't go into debt. If you are in debt, get out of it as quickly as you can.
Of course, when you're young you might be obliged to go into debt in order to get into your own home. A mortage is generally necessary to eventually purchase a house. But don't go overboard. Keep the mortage as small as you can to get that first home. You don't need brand new furniture, a swimming pool and two cars added to the debt you'll be carrying. And pay off as much as you can on the debt and as quickly as you can.
Too much debt is when it starts to dominate your thinking and gives you little peace. When you're forever chasing money to pay bills, etc.. If you start 'thinking poor' you'll continueto be poor.
Peace descends, when you're comfortable without beings wasteful, and always have enough put aside to meet any unexpected emergencies.