Grammar Drives Me Bananas

Enumerating first things first
Often makes me think I'm cursed.

"For item one, use firstly first."
This twisted English sounds the worst.

Firstly came my sister Jean.
Then came my brother in between.

And lastly came poor little me
But "lastly" drives me up a tree.

Why can't I say that "Jean came first"
Instead of sayng "firstly" first.

(c) 2006 Henry L. Lefevre