I sometimes forget how physically and mentally grueling ESB must have been for Mark. Buried in snow, repeatedly slapped by a Wampa hand on a pole, dunked in a giant aquarium, weeks if not months on a mudhole of a set with only Artoo, a rubber Muppet and various live reptiles to act opposite of. Not to mention the Vader duel!
On top of all that, he and his wife were expecting their first child during production. That’s stressful enough without being the lead in a Star Wars film to worry about.
Plus the weight training which apparently he hated! Mark was in killer shape on Empire. I saw an interview somewhere where he said he’d assumed he’d have to up the ante for Jedi - get even bigger and wear an eyepatch! I’d have been all for it (it’s a Conan thing)…