I'm vegetarian but I've spent a couple years as vegan when I was in my 20.

One day (I was 18, now I'm 40) I've decided to start choosing the vegetarian option whenever its available, after few days I realized that I was already vegetarian.

Being vegan is a completely different thing though, it require time, planning, knowledge and partecipation by the people around you. It can easily become a problem for everybody (not just you) and if you want your decision to be sustainable you don't want it. So my suggestion is to be smart, don't overdo, eventually start choosing the vegan option whenever is available or you have control on the meal preparation.