So dumb am I! If I had just done a bit more thinking I certainly could have figured that out…

1: re <=== subject line RE:
2: tin <=== tin man has no heart
3: o <=== ok, I admit I stole this one without knowing why
4: pa <=== this one, too
5: thy <=== in olden times of yore, "thy" was used instead of your

retinopathy… what do I win?