Play like you're 3

Medora’s 3. She likes to play. I guess all 3 years old like to play. When exactly do we quit liking to play? At my age I still play occasional, but not like when I was 3. 3 years old run- just for fun. Dance- just for fun. They can swing till their feet touch the sky. They can slid as fast as the wind. I saw some kids at the park clapping and walking on one of the picnic tables- they were maybe 10. Were they playing?
When does it change from play to work. And from want to- to have to. Can we play while we work? I used to work with a guy named Kelly, he always seemed to be giggling & having fun while he worked... maybe he was getting paid to play. I think we should all enjoy life... like we’re 3 again.