The human small intestine, which makes up the majority of the digestive tracts length, is filled with hemoreceptors, those are specifically for the breaking down of amino acids in meat, as they react with collagen. We have nothing similar for plant protein and have to rely on the ones for meat to break it down, which it's not very good at. Monogastric herbivores break down their food in their cecums, which make up 30-80% of their intestinal tract, the cecum in humans makes up less than 1%.
I'd suggest not taking your information from memes sent to you on facebook in future, unless you like proving your ignorance.
Was from a doctor actually, though yes, it was on the internet. And I also read it in one of Yuval Noah Harari's books.

