My high school's drama department put on the play "Our Town" during my junior year. The scene at the end where Emily says goodbye and asks, "Do any human beings ever realize life while they live it...every, every minute?" was truly impactful to me. We even discussed this in my English class, and the teacher made sure that we paid attention to the answer: "No. Saints and poets maybe...they do some." Well, I am neither one of those but I have made a conscious effort since then to "realize life" as much as possible.
This is probably one of the best versions of that scene that I have found. Paul Newman was one of my favorite actors. We don't really need the background music but this scene is perfectly executed: