Just noticed this thread and I wanted to mention to 22B that your son sounds similar to my DS15. And my DS15 has always seemed similar to me to my own older brother. When my older brother & I when were were in early elementary we were the most advanced students in a public school that let us more at our own pace. This was the 70's when public schools were experimenting with innovative teaching styles and we were left to move through the curriculum as fast as we wanted. And then we moved.
Skipping over a lot of details by H.S. my brother was one of those unmotivated gifted kids. Grades went up & down, had better things to do in H.S. than study. He would start failing, my parents would sit on him and his grades would go up. Bright could do anything his made up his mind to do. I found out recently that he wanted to take a year or two off school before going to college but that wasn't encouraged at the time and my parents didn't "let" him. Ended up a large university in a big city with a so-so reputation. He never graduated from college, we lost communications with him for a few years, he seemed to drift and try a lot of different low paying jobs for a number of years.
But eventually he found his nitch. It's not the job anyone would have dreamed for him when he was 10. He now owns and runs a unusual retail businesses, one he started by working as a clerk and quickly working his way up to head manager. Eventually the owner offered to sell it to him. He clearly has a comfortable and successful life. Not one that my parents or he would have expected when he was younger.
