I've thought of the " turning points " quite a few times, not out of regret or what could have been, just as what is.
As a child we are of course influenced by our parents. In our teen years we are influenced by our friends and just as much by our enemies, we worry about what others think about us, how others see us, whether were popular or good enough on the team , if were bullied, all of this molds us into who we will become, just at this point in our live we don't have an understanding of what Is happening or how its the same for everyone else also. (More or less).
When I was 25 and thought I had it all figured out someone made me see the world in a different light. They showed me its not all cut and dry or simple, but layered and one perspective is not always the only way to see things....through this person I was giving the book of 5 rings and the tao ta ching which led to zen and the understanding of Bushido, which progressed Into a strong study of philosophy and changed my life from that point on.
I know, that don't make any sence but that is the short version of one of the major turning points for me and how it was because of someone else. For me , in one of the most unlikely places to discover philosophy and it have a profound impact and changed the way I saw everything, was life changing....
A few years after that, I was at a highschool reunion. And realized how much we all influenced each other.we all influence our friends, and through them others we don't even know, they may be friends with ppl we didnt like but that little piece of us they carry around is left in the ppl they meet......our actions and intent spreads far.