My father donated his body to science. There were two surprises involved in that process - the first was that science was not entirely sure it wanted his cast-off 84-year-old body. When called, they were ambivalent, but then came and took a look and decided to comply with his wishes. Presumably he was in good enough shape. The second surprise was a year later when they called my mother and told her to come and pick up the ashes.
Since i knew for decades that his intention was to donate his body, it never seemed unusual to me. Only recently have i realized that he won't be on Find A Grave for any researching relatives to find. And only just now have i realized that i should put a note about it on his profile!