Don't be afraid of that voice inside your head.
Reading through the sports news today, I noticed a comment from Mikael Backlund of the Calgary Flames. He scored the overtime winner yesterday's hockey game and credited the pep talk he gave himself.
"That was something I've been dreaming of, something I've told myself before the third period I was going to do," Backlund said. "I've got to go in with that mindset if I want to play well. That's what I was just trying to tell myself.
"It was an amazing feeling. It's hard to describe. I didn't believe it went in at first but when I saw all the reaction and all the fans going crazy and my teammates going crazy, it's just an unbelievable feeling."
The best athletes and traders talk to themselves and reassure themselves with positive comments to build their confidence. When they're in a slump (Backlund hadn't scored a goal in the playoffs), they use that voice to get themselves in the right frame of mind.
Also note that Backlund wasn't always a good pro but has slowly developed into a higher-tier player. Could it be because of the mental game?
