I don't know if you are like I was before, but it's a lot easier to complain and be jealous of people, things & more than being positive. I don't know why, but in general, we are always looking for negative things instead of looking for positive things.
In the past year, I've been trying to be more positive and see positivity in very situation. It seems very simple to say, but it's a lot more difficult than that. However, it was worth it. I still work on that, because I feel like you can always see more positivity in your life, just by being thankful for what you have instead of looking at what you don't have.
I have realized by being more positive I was less anxious and stress. I was more calm and happy than ever. My relationship with some people around me get better and I become closer to some of them. Something that I am very grateful for. Every single day feels like a great day and feels wonderful because you see positivity everywhere, I know it's difficult because believe me I still learn to be positive every day and change my negative thoughts into good thoughts.
Further, being positive will not just change your day, but your life. Think about that, when you are negative or that something negative happens, most part of the time something others that are negative gonna happen too or the worst thing you imagine will happen. Well, when you are positive, more positive things will happen and the best you imagine will happen too. If it's not wonderful, I don't what is wonderful.
Try it for a day, be positive all day long, look at every situation in a positive way, be thankful for what you have and be positive than being negative and complain about what you don't have. Tell me if you saw a difference in how you feel and how your day as been. ! :)