There is definitely a personal/cultural/local factor to this because I am extremely aware gelatin is from dead animals and have known this for as long as I can remember. The other items are things I only realised when I started excluding animal products. Except for maybe carmine?
spoiler
Head cheese was a staple during holiday meals (I have never eaten it, it's fucking rank even if you don't know what it is). Mmmmm yes, let's boil an animals head and make a little cake out of it.
But there, it's added to the list and so gross it is going behind a spoiler.