Exercise: importance of workout confusion

Lately I've seen a lot on print and TV about muscle confusion. I decided to give it a try, my way. On a magazine that I saw last week, they suggested a new twist on muscle confussion. Take a very small weight and do a ridiculous amount of repetitions. I decided to do 100 bycep curls with a two pound weight. Sounds easy enough. I was going really fast for the first 50. And then my arm started to show signs of fatigue. I was able to make it, after many stops and starts. Then I had to repeat in the other arm! But you know what? I do this every four days. I have done it three times already (started last week), and the first day after, my arms hurt. Now they don't hurt. But I am still not capable of doing the full 100 without stopping. I figured after I can dominate this, I can go for three-pound weights, and I will let you know how it goes.
Oh, and by the way, this is on top of our regular routines, that is where the muscle confussion is. This is an unexpected add on. Keep trying!