Now We Are Six by A. A. Milne
 

When I was One,

I had just begun.

When I was Two,

I was nearly new.

When I was Three

I was hardly me.

When I was Four,

I was not much more.

When I was Five,

I was just alive.

But now I am Six,

I'm as clever as clever,

So I think I'll be six now for ever and ever.