In 2010, 46.9 million people were in poverty, up from 37.3 million in 2007. Almost 14 million people are unemployed. The cost of living has gone up 67% since 1990. Did your girlfriend go to college? The average college graduate has nearly $20,000 in debt.
I could go on for several more paragraphs about this, but instead I'll tell you to Google the Occupy movement and seriously hope that you educate yourself a little before you go spouting off about your girlfriend's supposed "gambling or drug problems."
As to the "Are some things off-limits to discuss?" part of your question: Within reason and in time, most conversations are not off-limits. I fail to see how someone else's debt affects you, though, unless y'all are planning to get joint bank accounts or open a business together.
I have friends who've been credit-jilted from bad divorces, for not being able to find a job after they were laid off, and for having to pay exorbitant medical bills without insurance. These are all intensely personal reasons for having a crappy credit history, and it's within a person's right to disclose or not disclose such histories. Your girlfriend has the same right. It's one thing if you notice she has a pesky habit of buying Lexuses, but there's a difference between accrued debt and reckless spending habits.
As we get to know our dating partners, financial histories and habits tend to come up organically, especially if you're semi-serious or headed down the road to matrimony. For instance, it's not unreasonable to have the money talk with someone you're moving in with. But wanting to exchange credit scores with someone you've just started shagging is weird, and mildly offensive.
Your girlfriend deserves someone with an ounce of compassion and understanding. Maybe in five years, after you've grown up some, gotten to know people outside of your socioeconomic bracket, and learned the difference between hard work and privilege, then you might have some perspective. I certainly hope you do, and not just for the sake of your poor (I don't mean that in the monetary sense) girlfriend. Also, if you are going to make arbitrary value judgments based on net worth, it would serve you well not to jump into being girlfriends with someone you don't know. It's not easy to vet someone's stock option potential in casual conversation, but it will save you a lot of time and aggravation, and it'll ensure the dating pool remains more open for people who care about things besides money.
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