Maybe take the time every once in a while do to something you liked doing as a child. Going to see a certain movie for nostalgia, building a tiny scene in a shoebox from sticks&stones and other random items, getting into lego, ÖOöOh especially things your parents wouldn't let you do because of reasons that don't hold up now that you're an adult and you CAN buy an entire cake and it it before dinner every day voor a week!

Sometimes all you have to do is give your inner child a clear signal that you're here for him, by doing something fun, even if it's just for that moment where you're just picking up rocks that you think look cool.