This phenomenon occurs in other contexts too; for instance, a person who's happily married will be happy for their best friend's happy marriage...but, a person who's unhappily single (or unhappily married) might resent their friend's happy marriage.

Honestly, I like to say my marriage is my #1 investment (15 years this month!)  

My first marriage ended in large part because of that. 

For 36 yrs of marriage, particularly when we were young and had a 12.25% APR mortgage and later an 8% mortgage, we were sold on the idea of paying off the primary residence quickly (8-12% interest was safer than trying for the same in mutual funds, and came with the "security" of trying to own the house without a mortgage.....along with the Biblical principal of debt-free living).

On holding a marriage together?

I have delayed marriage and having a family because there is no way I could work hours like this with kids.

I don't see how that is possible outside a relationship with Christ, personally, because some on this board, or in real estate, will endlessly acquire more and more properties, at the expense of their marriages, families, and their own health. 

For us, the commitment was made to marriage (engagement) and that was the point where both of us really were able to be 'all in' and work hand in hand on my wife's house at the time. 

My husband and I each had long term accounts prior to marriage that we both wanted to keep for the business relationship with the bank, but we added each other to them. 

That is like accepting marriage without sex.