It don't mean a thing if it ain't got that string! That's a fine platitude for any given situation (just try it!), but particularly on, today, National Yo-Yo Day.
Yo-yos have a long history, but their throw-disks-attached-to-string-down-and-the-thing-returns-to-your-hand technology has remained consistent since as far back as the time of ancient Greece! Those old-timey yo-yos, which were probably used by Hercules and Xena, got a whole lot better circa 1928. That's when the modern yo-yo was popularized in part by Pedro Flores, whose California-based Yo-yo Manufacturing Company shipped hundreds of thousands of the things out to kids all over the world.
These days we have yo-yos made from all manner of materials, with all kinds of fancy strings, but they still accomplish the same quality tricks -- tricks with names like "Walk the Dog," "Around the World" and "Hit Yourself In The Face And Cry."
May these comics inspire you to grab a yo-yo and practice at least two of those to your heart's content.