Im a vegetarian and i find that it has te be something you truly want and that you are really commited to. If thats the case it is easy, but if it is not you will have really hard time seeing everybody else eat meat.
What does help me is trying out nee vegetarian recipes. They are often soooo good and i dont even miss meat. Also, remember that being a vegetarian is really beneficial for your health :) watch documentaries like food inc of forks over knives to remind you of that fact.