It's just a thing that kids do. Haven't you ever seen a kid just hit someone with a stick or bite someone or some other forgeted up stuff then immediately make up a story like "it was an accident"? Really they just wanted to try it, then realized it feels bad man.
I half remember doing stuff relative to that. I kicked my friend's little brother really hard, when I was around 5. I don't remember why, but I remember being ashamed. And then taking presents from a party and hiding them in a vent... Again, when I was around 5.
However, there's an extent of which you lie towards. Usually it's the little loving starfishs who keep a lie going for as long as this.