my (M)ysterious guest

I have a mysterious guest.
He creeps up on me, with me being unaware.
When I am totally aware,
I can hear him go "thump. thump."
As he gets bolder, his sounds get louder.
He forces me to not ignore him.
Oh, my mysterious guest.

I wish he stopped creeping up on me like that.
I wish he would simply disappear.
Oh, my mysterious guest, Mr. M.
You wonder who my mysterious guest might be.
Well I'll say...

He's my bloody migraine.