Watch Your Head
Except in a mirror, it's not possible to watch your head. I can surmise why we use that phrase, but it really doesn't make literal sense.
On Table Bottom Awareness Day you do the flip side (literally) of what you did yesterday.
This day was invented to prevent discrimination lawsuits being initiated by the Table Bottoms Union. You don't want to arouse the ire of those folks.
Table bottoms (and by table bottoms, we do not mean the legs of a table but the underside) serve a very useful purpose that you might not have thought of before. They hold up the table tops.
Their most common purpose that everyone is aware of though is that they serve as a repository for used chewing gum - especially Juicy Fruit.
Juicy Fruit (my favorite when I used to chew gum back in the day) has a great flavor, but it doesn't last very long, relative to other gums like Big Red or Dentine.
That's why it's the most-often-found brand of gum on table bottoms. You have to start a new piece more often than other brands. Since table bottoms are more common and convenient that waste baskets...well, yeah.