This rhyme seems to be saying that whether you're a king or a "common" person, gravity still works the same for you...
Wear you a hat, or wear you a crown,
All that goes up must surely come down.
Thanks and Acknowledgements
This rhyme can be found in The Annotated Mother Goose (1962), in the section entitled "Mother Goose's Wise Sayings". I found it in The Little Mother Goose (1912), illustrated by Jessie Willcox Smith, and printed in the USA.