The real question embedded here isn't about levity at all—it's an interrogation of our habit to treat every moment as consequential, to armor ourselves against joy with significance. Nolan, a screenwriter drawn to complex moral dilemmas, recognizes that our obsession with seriousness often becomes another form of self-protection, a way to feel in control. When a parent spends an entire vacation mentally reviewing work problems instead of noticing their child's laughter, they're answering "yes" to this very question, having surrendered the present to an imagined future. The insight's power lies not in endorsing frivolousness, but in exposing how our grimness can be a choice rather than a necessity.