Can you trace back your growth as a person to a single point in your personal history?

While a fair amount of life changing stuff has happened to me (with respect to the fact that I am still quite young) but I realized that there is one point in my life that is directly and indirectly caused me to be who I am today. Sophomore year of high school, I changed my schedule to take ancient history second semester which pushed gym to first semester. Because of that, I met people I would never have met otherwise, other people met each other who wouldn’t have met and all sorts of things happened as a result of this one action. Can anyone else think of a seemingly unimportant moment that changed everything?