You may not know this but today is "National Puzzle Day!"
And doing puzzles as little as 15 minutes a day has been shown to help keep your mind sharp.
In fact, some researchers say elderly people who challenge their mind with puzzles can delay dementia or even lower the risk for Alzheimer's disease.
You can do jigsaw puzzles, crosswords, number games, or 3D puzzles - they all count.
Dr. Roxanne Sukol from the Cleveland Clinic says, "I don't think it matters a lot which one you do, as long as you pick something that you enjoy and keep working on it."