A Screw Loose

Good sense is governed so it's said,
In how the Lord screws on ones head.
When mine was due to be assembled,
Maybe the good Lords hands had trembled.

Although I'd thought that it was tight,
Some say it isn't screwed on right
Or why would I be wasting time
On nonsense verse and dubious rhyme?

I do not think my ancient head
Has either left or right hand thread,
Perhaps in haste then He made do ,
With just a single woodwork screw
And after years of constant use,
My screw has finally come loose.