[You’re just a retard.]
Many decades ago, had a high school acquaintance expire from a blood clot during gym class. Aneurysms have existed at least as long as written records. This kid was fit as a fiddle and just missed the cut for track and field. Many of these issues exist at birth, some as a product of the specific pregnancy and others as the result of bad genes. This is why, from time to time, physical exams are generally a good idea - you never know if there’s a time bomb ticking in there.