yes, simply because of the huge scale of the universe. It is ridiculous to think that out of the billion Billion galaxies. There's only one planet that supports life.
Well i wouldnt think that someone would just hand out a code to you, when they dont even know you. And as for free codes, dont trust the internet. You will get scammed.
I was always bad at halo 3, became alot better in Reach, that doesnt mean i cant see others who were slightly/alot better achieve it in a matter of hours.