Susan, you've hit the nail right on the head!
Everyone agrees to pay their HOA dues when they buy a condo or townhome in an association, and you are legally bound by that agreement. If you fail to pay, the association will put a lien on the property (meaning they get paid when you sell) or it can lead to foreclosure if, as Susan states, you don't pay your real estate tax as well. Believe me, the government is going to get paid.
If you have no mortgage and cannot keep your HOA dues current, you might want to consult with an accountant or attorney to discuss your situation and options. You want to try and avoid foreclosure if at all possible.
Hope this helps.
Keller Williams, Eagan