If you are working your ass off for subsistence, you snatch at chances for respite - any respite - when you get the chance. If you try to get ahead, most likely, any gains will be snatched from you by circumstance (health, accident, etc.) anyway, so the temptation to 'live for the moment' can be overwhelming. Especially since looking to the future can be REALLY depressing. It takes real strength, drive, stubbornness (in my case, bloody-minded anger) AND luck to escape.

When you have NO discretionary cash, and you've had what little gains you've made taken away from you repeatedly, when you live in despair - a tiny bit of luxury can keep you going.