I was watching the fourth OP opening and I thought of this: Which Straw Hat has had the saddest past? They've all been rightfully trauma'd, but who the most? Here's my rank, least to most:
7. Luffy: Shanks lost his arm, then left… not to much horror there.
6. Zoro: Yeah, Kuina died, but he still fights on in her honor, or something. Nothing too bad, in comparison to the others, anyway.
5. Usopp: His mother died, his father left. Sad, but not horrible.
4. Sanji: Starved on a rock, his soon-to-be mentor ate his own leg. Learned to never waste food. Hooray morals!
3. Chopper: His best (only) friend was poisoned... by Chopper himself. Then, he blew himself up. No friends. Pretty dang sad.
2. Nami: Now we get into the horrorble. Her entire town is taken over by pirates, and she watches her mother get shot in the head. Thrice.
1. Robin: Only survivor as she watched her entire island be unjustly genocide...ed. Yeah. No friends or family either, before that.
So, that's my analysis.
I have to agree with you on that List. Robin's past is the only one (well, except from Nami's and Chopper's) that makes me wanna squish the World Government flat. Or get Luffy to do it, that'd do a lot more damage psychologically ('cos the WG think he's weak) and physically (because he's actually potentially stronger than Whitebeard.)