I don't know if this really qualifies, but I thought it was a mustachian people problem.
This month is property tax bill month. For my mom, it is also the annual property insurance bill month (by coincidence) and six-month car insurance bill month. During the last year, my mom got tired of having mortgages and paid off both of her houses. I think she would have been better to invest that money, but she valued reducing her fixed expenses more. It's her money. She lives in one and "rents" the other to my sister. I say "rents" because it's not meant to make any money. My sister pays well below market rate, just what would be my mom's old mortgage payment.
Anyway, my mom was talking to me about this. And she was complaining because the taxes and insurance on both houses, plus her car insurance, was several thousand dollars. Her complaint? "It's not like I don't have more than enough money in my savings account, but do you realize that this is like $700 a month in taxes and insurance costs?! That is just stupid. That's what your sister pays me each month. Oh well, I'll just take what she gives me and throw it right back into savings for next year."
LOL, it was such a small thing for her to complain about. Really, she could cash-flow it over a couple months, if she wanted to. But, she just wants to keep her expenses as low as possible and she'd forgotten to include those in her normal budget. Less than $700 a month for two houses and car insurance isn't bad at all, and she doesn't even need to pay for it because my sister gives her enough to cover it.
My mom definitely has the "lower your costs" side of mustachianism down. She's afraid of aggressive investing, despite being only a few years away from a secure pension that more than covers her fixed costs.