I've actually experienced a bit of an opposite twist on what you say. I used to believe nothing could ever change, but as I age I become more and more sure that the world will of course change in my life time. My difference is that I don't presume to know how or why.
In the past 200 years, what generation hasn't experienced major world changes? There have consistently been rapid and life altering technological developments. National boundaries have changed through war and politics, whole new countries have even been created. Women were unable to vote in many places within this century, and still can't vote in places today. Slavery was not so long ago.
I think it's arrogant to think that the world won't change in our life time.