I saw a bit of this as an overseas defense contractor. Everyone was making six figures, some 200K or more, and a lot of them were blowing months worth of pay on 1-2 weeks off mid-tour, etc. The guy I replaced had been in Iraq for two years and grossed probably at least $400K (when I went it was $180K annualized but the danger pay had come down recently), was around 60 and had been employed in the field (mostly stateside) for like 25 years, and was retiring to live in a new house he'd built during his tour.
IT WAS MORTGAGED. And he had minimal equity! He'd spent most of his last year's pay on upgrades like landscaping and fountains, that is, whatever he didn't blow on 5-star hotels in Jordan and Dubai on his breaks. He was hoping his pension would cover the debt service and his other living costs, but he didn't sound so sure.
I spent my year over there, paid off all kinds of past financial mistakes, divorce settlement, car loans, etc, and came home with fifty grand in the bank. And my predecessor? When I got home, I heard he was queued up to go back over just to pay his bills. I cannot in my life fucking imagine how anyone could decide it's worth doing something like that unless you're going to change your life forever, for good, as a result.
I recently hosted (via AirBnB) a guy who's spent most of his life back and forth to Saudi Arabia and other places like that, and has little to show for it. Divorced, legal fights, child support, etc. He was going over with this plan to save up another 200 G's and bring it all home to start a new business. I hope it works out... may hear from him when he gets home and needs a place to stay.