He's a test pilot, right? I'm not saying that he should have zero willpower. But I don't understand why he would have incomparable willpower.
When I think of professions that require extreme willpower just to get through the day...test pilot doesn't pop into my head. Hell, A dedicated teacher would have more willpower than a test pilot. LOL.
For all you GL heads, let me know what I'm missin', as I'm sure there is some backstory to why Hal's will is so great.