"30 year old memories" do not make 9 autopsy doctors, all interviewed at different times and independently from eachother, each forget every detail about the most important autopsy they ever did and imagine that there was a big hole in the back of the president's head and that half of his skull was missing, when in fact there was only a tiny bullet size hole.
And BTW, anyone who watches the film of the assassination will see that part of his head was blown off. You can see chunks of his skull fly off and Jackie climbs onto the trunk of the limo to retrieve part of his head.
And that's what all the other witnesses said as well:
http://www.youtube.com/watch?v=JhWJowvbtxs&NR=1
But none of that mattered back in 1964, because the Warren Commission never interviewed any of the doctors from Parkland Hospital, they never interviewed the autopsy doctors from Bethesda, and the public did not get to see the Zapruder film until the 1980s when it was finally released to the public. What you don't know won't affect your opinion, and that was why most Americans believed the Warren Commission. Today less than 10% of Americans believe the Warren Commission. You can't get 90% of Americans to agree on anything, yet 90% think the Warren Commission was full of crap.