"but this vegan thing" -spoken like a true novice; have you personally done a 30 days trial run? It's only 30 days of your entire lifetime. We are not "all different" either; we have species specific nutrition. A Shark, eats fish. A Squirrel eats nuts. Horses eat green grass/plants. The species-specific nutrition applies unquestionably to our fruigivores physiology; of all human beings. I am not on Steemit to debate with energy-draining-skeptics, I am here to serve the awakening and aware; "NEXT!!!"
I encourage you try 30 days, before you reply. How can we know anything for certain, without personal experience? Peace be with you. I love u. 
Yes I have, 15 years ago - it made me feel sick as a dog.
Then I did the opposite and reversed a golf ball sized brain tumour using a WAPF diet.
And then started a WAPF chapter, and then set up a successful nutritional supplement business. (We actually sell a few products you might like, such as coconut oil)
http://www.frot.co.nz/design/wapf/
http://www.naturefoods.co.nz/
Spoken like a true novice :)
Not everyone who disagrees with you is clueless!