Many vegans I know have been vegetarians for some time, before switching to veganism.
What are some reasons for this? Why not going straight to veganism? Also, are there any benefits for not becoming vegan from the start?
This is not a duplicate of Reasons for being vegetarian or vegan other than ethical reasons? as this question is asking about the reasons people have to first become vegetarians and only then vegans, compared to going vegan from the start. As mentioned in the comments though, there is another question similar to this one. I still believe these two questions ask different things - this question asks for reasons that someone who already IS a vegetarian has, to become vegan, as opposed to omnivore considering veganism and thinking about vegetarianism as an intermediate step.