1. Girlfriend
2. Friends ie QB Shelley
3. He realized he wasn't going to be the man here at BYU. He would get playing time but he wouldn't be the featured back
I say this with no animus toward DHC. I am sure he is a fine young man and this is something he did which he thought was best for him. I hope it all works out for him and he enjoys his last year of being a college student or maybe the beginning of a masters program.
Not every one is destined to be a starter, let alone a star.
Only 1.6% of college starters make the NFL and the avg NFL career is 3.3 years.