For me, being a kid at heart means maintaining that sense of wonder for the world. Now granted I don’t spend much time around children, but the few I have interacted with are just an endless stream of questions about the world and how it works. They ask with no shame, or no expectation that they will need to remember this information for later, they ask purely so they can have an answer.
This is something that I am trying to embrace more in life – asking questions and researching topics that I find interesting, purely for the sheer joy of learning about something new. I very much doubt that any of it will ever be useful to my career, but it is quite exciting to fully through myself into a new form of study that is purely for the fun of it.