I can’t believe I never understood before. Steve literally crashed a plane into a glacier over the Tesseract. He lost his best friend and the opportunity to be with the love of his life over the Tesseract. Of course he’s pissed off and unwilling to help when Fury comes to bother him about the fucking Tesseract. This is the same fight he fought in during WWII. It’s the fight they told him he won when they defrosted him. Of course he’s mad. Probably betrayed and frustrated, too. Not only that, but at the time of The Avengers, Steve has been out of the ice for two weeks. He lost his best friend, the love of his life, everyone and everything he’s ever known two weeks ago. He fought Red Skull and saw the Tesseract vaporize him into thin air two weeks ago. And then Fury interrupts Steve’s PTSD flashback at the gym to tell him S.H.I.E.L.D. found the Tesseract and promptly lost it to yet another villain bent on world destruction, and Steve is all Jesus F. Christ, I JUST did this! And then, as if that wasn’t bad enough, Steve discovers that S.H.I.E.L.D. was using the Tesseract to build HYDRA weapons of mass destruction (because S.H.I.E.L.D. is HYDRA,