This is sort of correct, just worded wrong. The adhesive on post-it notes was invented by someone trying to find a stronger glue. He didn't know what to use it for when it came out weak. A couple of years later someone used it on slips of paper to mark his place in his hymnal. The next year or so 3M licensed the product and attempted to sell it.

NOT TRUE! I have recently found out that they were invented by someone who wanted to mark places in his hymnal at church without ripping up the pages with tape.