Not vegan but raw. I am not a bodybuilder, normal person interested in health and I think the raw diet is amazing. What convinced me? A documentary called "Breakthrough" about a guy and his family they all eat only raw things and further reading on raw diet in the internet. You might also consider being a frutarian or following the paleo diet but I dont think that is too good.
I am not yet eating only raw but that is the plan for this year.
The documentary is great and I think everyone should watch it. Even if you dont plan being raw or eating only this type of food. It is at least fun.