A lot of people — especially if they come from modest backgrounds and suddenly "make good" — have no money management skills.

This is an important observation.

My ex thought she did have good money management skills, and we often argued about that... but time gradually revealed that her actual skill was having excellent "NO money" management skills. She was great at navigating life when she only had $50 in her pocket and nine days till payday... but had no idea how to deal with managing a $9,000 paycheck.

What a modest background teaches you is how to make do when you have very little. These people often lose their orientation completely when the come into money.

This is a really, really important point and and not talked about often enough. When you're choosing a life partner, their money personality is massively important. Sex is a triviality compared to that because when you're into your third decade together regardless of how good it was in the beginning.

But if your money personalities are a big mismatch, you're in for pain that won't go away.