A lot of people change for good. Some people just fall off. Just trying to progress in anything, no matter what you're doing, I feel like any progression you make... some people aren't gonna be around you that were around you.
You have to have the service mentality in the sense that you subjugate your own ego, and you subjugate a large part of your own life to really helping other people, being successful on their behalf.
True happiness arises, in the first place, from the enjoyment of oneself, and in the next, from the friendship and conversation of a few select companions.
An honest private man often grows cruel and abandoned when converted into an absolute prince. Give a man power of doing what he pleases with impunity, you extinguish his fear, and consequently overturn in him one of the great pillars of morality.