Let me begin by making an important distinction. Playfulness is Not the opposite of Responsible. Let me repeat that: Playfulness is not the opposite of responsible. In my mind the opposite of playfulness is seriousness; a total lack of humour, silliness, and whimsy.
Certainly there are a number of silly and irresponsible people in this world. Just as you can find people who are deadly serious yet very irresponsible. These are two distinct scales.
I mention this because most people feel that to be playful or silly is counterproductive or even the antithesis of being a rational and responsible adult.
Try that idea on for size and consider what it might mean for you. 😁