Engine weights

Why is it so hard for me to believe a slant 6 only weighs 475lbs?
Maybe you've wrestled with trying to stand one upright against the front bed of a truck before? Lol they are awkwardly shaped @475lbs.
I watched my brother who's 225lbs struggle and almost hurt himself doing it. Lol thing kept slipping and spinning around and wanting to land on his foot or leg.