In my opinion, the lessons learned in school or college are not related to work, I myself majored in photography, but after graduating from education I worked in a coffee shop, until now I am pursuing work as a coffee brewer or barista, although occasionally I also using my photographer skills. It's true what you said that success depends on yourself and your ambitions. If you really want to be successful then we will try to do our best. Lessons learned at school or college cannot be used as a benchmark for success.
I think what you are referring to above is that the most useful knowledge after college are the characters we develop along the way (i.e. perseverance, resilience, patience, being teachable, etc). The theoretical knowledge that we learn regarding our course are nothing compared to the virtues that we acquire.
I am a Civil Engineering graduate and currently practicing it but also studying my post-graduate degree in Development Economics at the same time. During the course of our life, we may shift our interest from one thing to another, or pursue a different career path than the degree we got after graduating college. However, the virtues that we acquire are still within us.
As one of my bosses always say, skills can be learned and a newbie can be taught about technical things. However, character cannot be changed in a small period of time. Hence, always choose good character employees than highly skilled ones that cannot be trusted.