I have said this before.
I got started in serious investing in 1997 when I discovered the Motley Fool.
A year and a half later mortgage rates has dropped and we went to refinance our mortgage. From 14% (Thanks, Jimmy Carter) to 8%.

I ran the numbers and told my wife, "We can either do a straight refi and reduce the monthly payment, or we can take $20,000 cash back and the payment will be the same as we pay now. It looks like if I had invested serious money in Motley Fool Foolish Four method we would have made a large gain and I think that this will continue."

She said "We are not having any trouble making the current payment, so even if you lose the entire $20,000 we would still be okay. Anyway, we were flat broke when we got married so we would not be any worse off than when we started."

I said, "Okay, we'll take the $20,000 and I'll invest it. I will keep track of what the mortgage balance would be if we didn't take the money, and compare that to the investment value. In a few years we will know if we made a mistake or not.
And whenever the investment account gets as big as the remaining mortgage balance, I will tell you and we can decide if we want to sell the stocks and pay off the house."

A few years later the stocks _had_ grown to be more than what we owed on the house, so I presented it to her and said, "Do we want to pay off the house now?" Fully expecting as a typical woman she would want to pay off the house.

She said, "Are you nuts? Keep investing. Just tell me when we have enough that we can retire."

When a bear market hit, and when I got a call from the broker demanding me to wire money and meet the margin call, and the times we were down 50%, she just said "Just tell me when I should stop spending money."
Unusual woman.

My friend at work, also doing Motley Fool, his wife insisted on paying off their house ASAP. After I retired (early) he was still prioritizing the mortgage, still working on getting it paid off when he got caught in a layoff a few years later.