Please pardon my philosophical tangents.

I've always thought of humanity as being in a transitional stage - the people we aren't now, we will one day become. Just like cultural trends, people also change.

For once, I'm questioning this, because in the short, insignificant amount of time I've been alive, I don't think I've really witnessed enough evidence to find the above statement true.

If somebody is frustruating me, a friend will often say something along the lines of "give it time, he/she will come around." The question though, is, will they? Does the average person really transform that much? I feel like I've transformed more than most, because I've had to acommodate for my own limitations, but do most other people experience the same thing? 

Or, and I know this is sad: do people continue to go about their ways, blind to how they are affecting those around them, potentially hurting many loved ones along the way while only acknowledging their own needs?

What I think I'm trying to ask here is, what are the limitations of change?