Originally Posted by DannoXYZ
First, forget the stupid "righty-tighty/leftie-loosie" technique. Learn the "right-hand rule" for threading. Similar to electro-magnetism in physics. Grab the spoke in your right palm. Orient your thumb in the direction you want to move the nipple. Point your thumb towards the hub to tighten, towards the rim to loosen. Your fingers will then aim in the direction you want to spin the nipple.
There is an easier way to remember the correct direction.
When turning the nipple imagine that you are putting a lid (the nipple) on a jar (the spoke). The spoke threads (jar opening) points towards the rim.
If you think about the problem like this, you don't have to think of spokes as threaded backwards.
BTW, don't give up. You have simply incurred an educational expense. I guarantee you won't make that same mistake again.