Brook admitted that the fight with Golovkin broke him

“That was the first time someone got into my head before a fight. I remember sitting in the hotel and thinking: “Tomorrow I’m going to fight Golovkin.” Honestly, I began to doubt myself. I had a nutritionist with me and I didn’t tell him I was going to lose, but I asked him, “I can win this fight, right?” Looking back, Gennady Golovkin was a monster. He was undefeated and believed that he could beat anyone, even a middleweight. I thought I could box him and keep my distance, which we know didn't happen. This fight broke me and changed me in many ways.”