Plants - don't know them near as well as I'd like.
medical - I've done a lot of training on this, but all it does is make me wish I knew more.
Traps/snares - working on it.
Music - won't do well without it.
Intelligent conversation - won't do well without it either.
People - I'm not an extrovert, but I'd go nuts all by myself. I'd probably be that guy who talks to his dog ... wait, I already am!
And I want to just acknowledge what has been said before - wife, and kids. For me, my wife is not a prepper, not a shooter, not a hunter, likes her comforts, etc. Now I dragged her all over the horn of africa so she knows how to do without, but she hates it. So its not so much a skill issue, as an attitude issue - I worry some days about depression in her, will to live, survive, if it came down to it. Beyond that, I've got guns & gear set up just for her.