I don’t know exactly what it means to be a kid at heart, but when my wife says it about me, it’s usually because I’ve been excited by wonder, novelty, or curiosity (or all three).
Adults reaction to anything — or lack of — is because it’s not new, it’s something they see or do every day. Or they’re so cynical that something with even the thinnest veneer of fun is rejected because it’s too simplistic, or just a way to grab attention to part one from their money.
Kids don’t see it that way. The ephemeral can seem meaningful to them. Experiences that we take for granted may be a first for them. The promises made by advertising will be exactly what they seem. Every now and then, I can drop the cynicism and decide that, you know what? Yes, this thing is exciting.
That’s when she says (lovingly, of course), “You’re just a big kid sometimes.”