#16: Not Your Business
This, in my opinion, is not a controversial personal finance take; this is an extremely sensible and necessary personal finance take. If you’re living in a house that doesn’t belong to you—whether you are renting it from a landlord or the house belongs to a romantic partner—you need to be aware that any money that you put into repairs or upgrades on that house is lost to you.
If you do it in your own house, it’s an investment. But if it’s a house you rent, I doubt the landlord is going to give you your granite countertops back when you move out. And with a romantic partner, as much as you think this is going to last forever, there’s a very real chance it won’t. If you guys break up, the money you spent on their house is money that you see no benefit from.