I’ll call it now - speak to that guy in a few years and he’ll be one of those, “I used to be vegan, but I stopped because I couldn’t stay healthy” people. He may even double-down and say that nobody can be healthy while vegan, because he personally couldn’t do it.

I’ve met plenty of those over my 20+ years of veganism. Learning about nutrition to make sure you get a balanced diet isn’t that hard - resources are everywhere. Honestly, such skills should be practiced by everyone, whether vegan or not. A lot of people don’t realize how unbalanced their diets are until they go to a doctor’s check-up in their 30s and get a surprising blood test result.