Still not used to their weird thread view
Where when you click the trash can button when you're viewing any one of the messages in the thread, everything goes to the trash. Everything, even messages you've sent in that thread, disappears when you click on the button when viewing the thread.
I had a long debate in the Gmail forums with one person -and I have to reckon that he/she was really trying to help me- teaching me to "understand" how it works, and myself responding how unintuitive and brain damaged was that decision because it violated one of the basic laws of UI designs: avoid unintended consequences. In the end, I had to close the discussion saying something like "hey, I know how it works, it is just I don't like it, and if you find it natural or intuitive you've been using this for too long because it is weird. And yes, I understand there is other option to view to switch but this is the default and defaults should be sane"
What amazed me was that this person could not even start to imagine that someone could not like this behavior. That one wanted to keep a copy of the sent messages regardless of them being part of a thread or not was an alien concept for him/her.
Funny how what is weird for some can be normal for others.