(Cleveland) - The largest lottery jackpot in U.S. history continues to grow. The Powerball grand prize is now at $800 million as more hopeful millionaires continue to buy tickets.

The odds of winning are astronomical, but the potentially huge reward has millions giving it a shot. Cleveland Clinic psychologist Joseph Rock says that your brain isn’t too worried about your odds of taking home the big prize.

“Our brains aren’t wired to think about probability. We understand the chances aren’t that good, but we can delude ourselves, and ‘hey I’ve got as good as a chance as anybody.”

According to Dr. Rock, everyone wants to dream and there is actually a part of our brains where fantasy is almost as good as reality.

Folks like to think about what they would do if they won the money - a new house, a new car or perhaps a lavish vacation.

Ohio lottery players (Photos by Ken Robinson/WTAM)

Dr. Rock says there are hormones that are released when we fantasize that can make us feel better, but for folks who spend too much of their income on lottery tickets, it could be a sign of a gambling problem.

“It’s low level gambling if you’re kicking in a couple of bucks, but I’ve also talked to people who are, you know, spending a hundred, two-hundred dollars a week and they think this is how they’re going to make their living, that becomes problematic.”

Rock believes most people can keep their lottery expectations realistic, but for folks struggling with gambling issues, he suggests avoiding the temptation to buy tickets by keeping cash out of sight.

The big drawing is tomorrow night.

(Cover photo by Ken Robinson/WTAM)

(c) 2016 by iHeartMedia, Inc.