The best thing about watermelon seeds is you can pinch them between your fingers and shot them at your friends face. I remember doing that all the time in school. I didn't have many friends though.
Food for thought, how come they don't make seedless mangos or avocados?
Lol...
May be because they have a single, large seed. So, no one is really disturbed or concerned about it presence during consumption.
That sounds logical.