The printing press is one of the most important inventions in the last 500 years. Not only did it deliver The Bible into the hands of the commons–it also challenged the authority of the church and its clergy, and literacy shot up as a result. Scribes were no longer valuable which rocked the whole industry of how literature was distributed.
While the printing press solved many problems, it created more. Once people were handed a book, many realized they were far-sighted. So, spectacles all of sudden became an important commodity. Which led to the innovation of glass. And with that innovation came microscropes that eventually discovered germs. At the same time, others were looking into the sky with now invented microscopes. Which in term, led to the discovery that we were no longer the center of the universe.
This is the effect that one change can make. Each of us has a far more reach than we even realize.
HT How we got here