My ex BIL is one. Born and raised in Southampton, NY to 2 surgeons. The whole 8 bedroom and 12 bathroom upbringing.
2 PhDs and from Stanford and Harvard Med, but absolutely clueless about real life outside Academia.
He knows what he knows very well, but little else.
My late husband was the most intelligent person I have ever been around. As a high school student, he talked his school into offering physics and other higher education courses. He could fix anything and he and a friend built a large bass fishing boat when he wasn't at NASA. He was a ham radio operator and built his first rig before he was a teenager. He fixed anything around the house. My daughter and I have talked about his IQ and wondered just how high it was. We went to Houston a few years before his death. A friend had taken some classes with him. He said that one day a prof was going down the roll telling each how many classes each had missed and the grade. When he got to my husband the prof told him he had missed more classes than anyone else but it did not matter since he had the highest grade. He majored in physics. We miss him.