Now that is a very interesting query. It brings a few things to mind.
People do change! They just don't think about it. We change the style of clothes we wear. We change our habits of communication. We change the meaning of some of the words we use. We change jobs. We change spouses. We change residences. We age, therefore, we change. But we don't think about intentional change very much at all. And when we do think about it, I would suggest that we do so because we are forced to, mostly, not because we want to.
Another thought I have is that we do not think so much of changing the world as we think of the need of “others” to change. There is a sense in which we believe that if everyone was like us – thought like us, acted like us – the world would indeed change and be much better. But then if you reconsider my premise in the former paragraph, having everyone be like us would be quite disastrous.
Then there is the whole matter that though we might give some consideration to changing the world, we often do so without contemplating how the world has already changed and is changing – whether we give it a thought or not. Some of the thinking about changing the world is NOT forward thinking. Such thinkers would have us go back in time. And some thinking about changing the world is, for me, too radically forward. In both of these instances, the thinkers are clearly not giving any consideration to the wisdom of self-change.
And, finally, there are those who do understand that changing the world means changing themselves. And they are tremendously frightened! If you know what you know for having lived with it and through it for the past 40 or 50 or 60 years, how will you live in a changed world about which you know so very little, if anything at all? We are not frightened by change. We experience too much of it in our lives day by day to be scared of it. We are frightened by that which we do not know: what will be the result of the change and will we be able to live in it, with it, through it.