What is a one-sentence summary of the following article?
Smiling costs nothing and it helps you to glow. Smiling helps you to feel better. And it's one of the best things you can give another human being. A smile will always make you look amazing. Change the things about you you're not happy with, but only because you know you can do or be better, not because someone else prefers you to be something else. Learn how to spot the difference; if you feel pressured, it usually means that someone or something else is raising your expectations to change, not you. That is a recipe for losing yourself, not gaining the best from yourself. Happiness is fleeting, contentment and fulfillment are enduring. Contentment with life isn't about getting stuck; it's about appreciating what you do have already and knowing that, in spite of setbacks (of which there will be plenty throughout life), you have the ability to keep going and to continually grow stronger. As the saying goes, everyone in life is doing it tough somewhere, some of the time. Kindness can be the helping hand that another person needs, and kind people are awesome. If that isn't about looking amazing, then what is?  Be nice to the people you come across in life. It takes the same amount of energy to be nice as it does to be mean, with the difference being that kindness opens up opportunities, while meanness shuts them down. Moreover, a mean-spirited heart carries many a burden that a kindhearted person doesn't have to bear. Being kind and thoughtful towards others has its own attractiveness; you can feel like a role model for the better world we'd all like to live in.

Summary:
Smile a lot more. Accept who you are. Seek to be fulfilled. Be kind to people.