Bay seniors who enjoy the ageless challenge of jigsaw puzzles should stop by Jigsaw Java in Redwood City this Saturday for the National Puzzle Day competition. Teams will be seeing who can complete a 1,000 piece puzzle fastest. If you’d like to get your grandchildren to pay more attention to you, give them a puzzle made from a family photograph starting at $15.95. And I read that doing puzzles like this, crosswords and Scrabble is recommended for staving off dementia. I forget where I read it.