I've always thought it meant that he can be better, but just not now, not that he could find a better girl.

Sort of like the lyric in Half of my Heart:  "I can only fall short for so long."  I really love that line.

I told a professional about The Hurt lyric, "I want to fall asleep in the arms of someone who doesn't deserve my love", I think that's it, and he said, "that's dangerous."