Why I should be vegan

Today I asked one of my vegan friends why I should be vegan, he told me he didnt want to preach to me, and he did a bad job of it when he tried honestly. I then got thinking why would I be vegan, I dont care about the animals feelings so much. I think its a waste to kill something to acess its goods. What it has come down to for me is the environmental impact of it all. I used to care about the animals that kept me vegetarian, then I asked myself why? I realised I didnt care about the animals, I cared about the efficiany, so I have decided I have my reason for being vegan in the next few months. Eating at a lower trophic level is more efficiant. It still all boils down to my selfishness. I could be vegan, I would be good at it. If I wasn't a vegan it would be a waste of me being here I guess in a way. I still haven't figured it all out yet. I will let you know when I do.