He was born in 1946. Based on the years of attendance, that means he went to this academy from age 13 to 18. Perhaps it was not reported because the media doesn't tend to report on a presidential candidate's MIDDLE AND HIGH SCHOOL RECORDS. This was a boarding/prep school with a military-type structure - it wasn't West Point.
But yeah, it is interesting how he played so many sports when he was also physically unfit for the draft. Almost as if his gastroenterologist who said he would be the healthiest president ever (HA!) was the SECOND doctor who got paid to write him a note.
