Sometimes people cherish the grandiose idea or even pursue the noble self-assigned objective of changing the world.
Can one change the world? Can a group of people do it?
Only people with power can "change the world," which usually means that they take over from a previous ruling class. They also have the habit of having useful idiots at hand.
Occasionally, people in power embrace and institutionalize the ideas of a new interest group, because the ideas are more profitable for the powerful than the previous ideas employed in the ideologies that have been sustaining the prevalent social construct. This is what happened in Ancient Rome, when the rulers switched from slavery to the colonus system, because the latter turned out to be cheaper to sustain and more productive, that is, more profitable: people, who are engaged in cropshare possessed the incentive to produce more, because they had to pay only a certain percentage of their produce for rent. They also felt better, because they were told they were “free,” although their freedom comprised free movement (if they had the money to move), free selection of their masters, having to take care of themselves and their families, and becoming fully responsible for their actions (despite being forced to make the same “decisions” over and over again). Moreover, if your slave caused damage, it was unwise to mete out harsh punishment, because you needed his work today, too, but your laborer can always be penalized by deducting the damage from his wages.
Of course, the option of conquest is always there, which definitely changes the lives (the “world”?) of the conquered. It is usually the militarily more advanced culture that prevails (which proves that “multiculturalism” is a lie, but in “multiculturalism” ALL cultures are erased and replaced with a nameless one); sometimes it is the conquerors who adopt the culture of the conquered (e.g. many Romans spoke Greek, not Latin), but assimilation or eradication can also happen instead.
Sorry to disappoint the over-ambitious, but “the world,” that is, the way humans have structured their social constructs in which they experience themselves and each other, has always followed the same pattern, as I described it earlier: