Nelson Dellis can memorize more than nine decks of cards — repeating each card in the order in which they were presented to him — in 30 minutes. In 15 minutes, he'll rattle off 201 names you mentioned to him only once.
Dellis, 33, is a four-time champion of the USA Memory competition, an annual event at which individuals attempt to memorize as much information as possible.
"When you have a good memory, you have better confidence in your memory," Dellis tells CNBC. "When you have that confidence, then you can focus your mental energy on other things, like being a good leader, boss, employee, speaker, influencer — whatever."
Boosting your memory and becoming more mentally sharp is easier than people think, Dellis says. A simple daily exercise that he recommends can dramatically improve your cognitive abilities, boost your confidence and help stave off memory loss.