Yes yes yes. He is in far too small a tank.

This kind of behavior is why they set tank limits for slightly larger fish. I.e. a neon blue dwarf gourami should be in a 30+ gallon aquarium (
www.liveaquaria.com).
I kept my (deceased by heater burn despite a heater guard) NBDG in a 10 gallon as temporary housing for about a week. He went insane, circling up and down against the glass on the left side of my aquarium. He was very unhappy to be there...
1) Is this your fault? I'm not the type to point fingers at the consumer. So I'd say *no.* I'm guessing the various advertisements around your
LFS had you believing that a medium-sized aquarium fish would be fine in a small aquarium. Unfortunately, with NBDGs (as with most fish) this is really not the case. I'm sure other site members have them in 10 gallons, but most ppl move them because they become either insane or territorial. They're emotionally sensitive fish.
2) How to remedy this? The behavior will continue as you've seen it, because the gourami feels claustrophobic (if you will). Tough choice: either resign yourself to getting a larger tank (see my signature line--this isn't a bad thing) or return him to the store. I have a feeling you will see aggressive behavior from him also, though DGs are generally aggressive to members of their own species the most.
Perhaps not the answer you wanted, but I've certainly seen this behavior before, and it's not healthy...
HTH 