I think we all have our different backgrounds and experiences which might sound the same but weren't really. Our age, natural temperaments, surroundings (number, age, gender of siblings, for example), there's so much that goes into our experiences that can't be duplicated.

Just your thinking. . . "they've gone on to become successful doctors, lawyers, business owners, artists, musicians, scientists, writers, leaders, teachers, etc. ..." as if there is an automatic "becoming" that happens and that you have missed; I was 57 when I got the degree I went after starting when I was 16 and I consider myself "successful". To me, artists are those who create art; musicians, those who make music; writers, those who write, etc. Not everyone's path is the same or even as "successful" as it may appear to someone on the outside? You probably look quite successful to someone else, despite how you feel.