1. Spending your money on unnecessary items immediately the money arrives. Trying to prove a point to people by living a standard that is above your pay grade.
The usual reason why a lot of people think this way after getting their money or paycheck is because after working everyday, they usually think that "I deserve this because I worked for it". Tho of course, you also deserve to treat yourself once in a while, but doing it every paycheck or spending on unnecessary things whenever you have money isn't a smart way of handling your finances. Sometimes others would even allocate their money already on the things they want to buy or spend even if they haven't received their money yet. It's like they're look forward for their salary just to spend it. Only allocating a small percentage on saving or investment/business goals.
2. Live on one source of income. Everyday of our life our responsibilities and challenges keeps piling up accumulating without consideration to our financial capability. The economy and cost of living continue getting worsen. So in order not to be able to beat this piling settle comfortably on a single source of income flow.
Most rich or successful people reached that stage because they have their own businesses or investments. If you stick with working 8 hours everyday for someone else's businesses, the chances of improving your finances are low. Only few employees get a chance to earn bigger salary, and sometimes it'll take them decades of working before they can reach that range of profit. So if you want to maximize your skills and opportunities as early as you can, find another sources of income and don't just be satisfied having one. Most of the time, that one source of income you have isn't even enough for your living expenses.
3. Become an extremely cheerful giver/lender to friends and family. A wisdom quote I read somewhere said, "if you want to lose your friends and family lend them money". Keeping doing this and you going to be successfully poor.
It's fine to sometimes give your family as an appreciation or thank you. But lending would be a bit harder cause sometimes even if it's your relatives, it can still be hard to ask them to pay you back. Same goes with your friends. You may treat them as a friend but there are people that when money involves, they wouldn't care. So always be careful lending your money to others even if it's close to you.
4.Learn how not to mind your own business, making every events around you your concern even when it doesn't affect you. It's a nice way to make cool enemies. Etc.
Just focus on your life. Focus on achieving your goal and not other people's lives. Aside from the reason that it can cause you a lot of enemies, you would also be wasting your precious time on something that won't even bring you any good nor benefits.