My brother-in-law saw me lugging leveling compound into the house and said "I have two words for you - you know I'm handy with things around the house, and I see what you're carrying in, and I have two words: sticky tiles."
Well, it turns out that would have been a better idea. I got the leveling compound down, amidst much cursing and groaning, and I got the linoleum sheet down on it. It looks kinda sorta okay. But when you walk on it, you can feel the imperfections. So, a lot of effort for substandard results. Still, it's done, which is a good thing.
So why, after receiving good advice, did I ignore it? I knew that my fingers are less than deft and would have trouble smoothing and leveling in time before that junk dried. I knew I was inexperienced at the whole deal. I knew that the hardware store was only a mile away, and that I could, actually, return the unopened 25 bag of powder. In retrospect, it would even have been better to put the sheet down over the old floor where I had scraped up ancient linoleum tiles. Yeah, that's wrong, but it would still have been better than what I ended up with.
Economists refer to the idea of "sunk cost," and how it influences economic behavior irrationally. I had already bought the sheet of linoleum. I had already bought a second bag of compound at $21 (having screwed up the first batch despite following the directions). Getting sticky tiles would involve making another decision about style, buying more stuff - including grout. The rational part of my brain, which my BIL was trying to appeal to, was getting overruled by the irrational part that says You're already waist-deep in this linoleum idea. You don't want to give that away.
The reason why it figures so prominently in economics - and sociology and psychology - is precisely because of this irrationality. The cost of the linoleum sheet is sunk. The cost of the first bag is sunk. Nothing can be done about it, and it should have no influence on the question "What is the best thing to be done now?" But it does have an influence. We grow attached to something merely because we have invested in it. And it's irrational. You can see it all around you in politics, in diplomacy, in business, in relationships - and in redoing bathroom floors. Sunk cost. Remember it.
This is the real value of a liberal arts education, BTW. You can develop intelligent-sounding explanations for everything you screw up. Which frankly, I find valuable. The next person who owns this house will not be impressed that I can rationalise so well. But heck, I don't even know the guy. I don't care.