A simple smile can turn around anyone's day for the better. A smile from people you smile to can actually guarantee it. That smile they gave you can make them more up beat for work that day, or make them forget about a problem and help them focus more on what's at hand. It's an imprint that you make, although not permanent, that will change the course of that day for them. I try to do that all the time. Letting someone take your spot in the elevator while smiling at them. These are actions that people shrug off at the end of day, but what they remember is that the day was different. You made it different. It's not a lasting change, but hey, it's something to be proud of.
Being the best at what you do is one thing, helping people be the best at what they do is another. To end, here is a video that I find really inspiring. Get a group of friends and try it out! Enjoy! :)