I'm an amateur linguist (hopefully I will get a degree in the field).
I started learning languages in middle school. I started conlanging before I even knew what conlanging was. I created my own world with countries and different political systems (I was obsessed--to the point that I even designed important buildings like palaces and museuems, including what the interior design looked like). I designed flags for my countries as well.
I was definitely a bored kid so I put all my creative energy into my little fantasy world. (I can't say I didn't "plagiarize" certain parts of our real Earth--I was a middle schooler!)