Why did James Bradley wait so long to tell this compelling story?

Bradley said he had waited a year to examine the evidence in the newspaper article because he was working on a new book in Vietnam, and then became ill. He did not come forward with his belief that his father was not in the photograph, he said, because there was little interest from the news media and the Marines. (I have no idea what story but at least I tried . So, so, so, sorry if this doesn’t help.)