Before even taking the Marvel role, Brolin sought advice from Mark Ruffalo. "I called Ruffalo, who I've known for a long time, and I said 'Hey man, what do you think? Like should I do this?' And he goes, 'You'll feel more out of sorts than you've ever felt because you have a Velcro onesie on, you have dots on your face, you have a helmet with a cam. But when you ultimately see it you'll be blown away,'" Brolin recalled. "So then when I saw Mark honestly four years later on the set, he was in his onesie, I was in my onesie. We both had our dots. We walked toward each other and he goes 'I'm so done with this.'"
Of course, now that Brolin is playing the Mad Titan Thanos, you would think his family would be excited about his new major role. Wrong. Brolin revealed his brother, who he called a comic book "fanatic," had a few questions for him playing Thanos. 1: "Why?" 2: "What are you doing to prep?" Unfortunately, his brother was not impressed with Brolin's preparations. "That's totally wrong," he told him. Brolin's brother even turned down the offer to attend the premiere with him. "He chose not to be at the premiere because he wanted to see it in a group with his friends." Ouch.
During his time on Jimmy Kimmel Live! alongside Chris Hemsworth, Chadwick Boseman, Karen Gillan, and Sebastian Stan, Brolin also drew Thanos' "scrotum face," claimed he stole a "leopard-skin thong" from Thanos' wardrobe, and accused Hemsworth of stealing his shine since the Thor star was wearing a purple suit.