This overall answer is going to be quite dark but as a child, I had an extensive career progression plan too. I wanted to be a clinical psychologist from a young age after I went through an eating disorder at 10 where I couldn't eat for months due to severe anxiety. I think most children and myself included, would have never considered the importance of mental health at that age let alone dedicating their entire life to its treatment and support. It was my dream for years too but I changed my mind in the end and extensively planned out an entirely different career at 17. I'm not sure if I regret changing my mind but we'll see.
Reflecting back on when I was a child, I saw a lot of people go through their own personal struggles with their mental health. Whether it was within my family or people I met online, I took the time to educate myself about how to best be supportive from a very young age and l prepared extensively on what I would do should it improve, worsen or reach a critical state. After an experience where a friend was suicidal when I was 12, I felt so inadequate in how much I could help them and morbidly thought about how I should prepare for next time if I ever met someone else who reached that point. What I would say, who would I get to help (would I call someone?) etc.
On a less dark note, I also used to prepare for job interview questions as a child? I was 10 or 11 and had a scholarship interview for high school so I extensively practiced. I even had my parents critique my responses and give me feedback. It helped a lot I think - I sounded a lot more prepared and confident than I would have been had I not taken the time. Now at university where I do tons of interviews for either jobs, uni societies etc. I'm a lot calmer because I took so much time as a child to learn how to best articulate my response to a lot of the common questions. I think practicing also helped me understand my own personal values and skillset extremely well which helps a lot when adapting my responses for different types of organisations. :D