The first teeth you get immediately after birth just like you get your first opinions from your parents and social environment. Later in life you develop your own opinions just like you lose your original teeth (called milk teeth) and develop more permanent ones that are probably gonna last you a lifetime.
I think most people form most of their worldview around the age of 12 to 14 years. I know I did, that is when I first learned about most of the issues I am still most passionate about nowadays. Anything I learned about earlier or later, I am more likely to change my mind about.
Maybe. I could be an edge case, but I don’t even think current me and 14 year old me could have a civilized discussion about anything we care about xD
Current me and 14-year-old me would certainly agree that Linux (and free software generally) is awesome for example. :D