<human>: Had no idea that $400 would screw me so hard.. here is my dilemma-

I had a gym membership over 3 years ago that went into collections due to non-payment as a result of being an idiot and not having a job, then paid off as soon as i got a job; fast forward to the future, now I have a very good debt to income ratio, have been paying everything on time since the aforementioned, but I can't even open a second credit card. 

I make $45k a year now, have only $125/mo student loans, $525 rent, only $500 left on a credit card, and I get denied for even a second credit card, which scares me because I want to buy a house with my future wife in 2012. Its listed as a chargeoff, even though it is paid off?

Can you give me a shortened version of the text?
<bot>: $400 gym membership dues that got paid off caused derogatory mark on credit, 3 years later still cannot open new lines of credit