I admit, as I get older, I become more and more self-centered, and no doubt, less willing to help others too.
I still remember, when I was still so young, so naive, I was a hyperactive child and always tried my best to help others; but no, not now, never.
It's due to the environment, sometimes people, in order to get themselves adapt with the new surroundings, they'll need to change. There are infinite of examples out there - turning evil, hiding their true faces behind a mask being one of them.
Just scold, just hate, just ignore, just bla bla bla...I'm just me anyway. People are so insincere these days, including me myself...