My friends had recently taught me something about sincerity.
Defination of it is, treating your friends with sincere heart without hoping any repayment from them.
It's one of the best things I had learnt in my life. Being frank, I know I don't really treat every of my friend with 100% sincerity. Quite hard to so though, I presume.
Trying to work hard to achieve more, and improve myself more.
People out there, work hard too! Gambate!