Some of us were discussing the "rules" which are based on archaic or even Latin grammar ("Do not split an infinitive, and yes, I mean you, Captain Kirk, with your to boldly go!" "Do not end on a preposition!).
I would say don't believe in the "rule" about not ending with a preposition. However, I do want to point out that the end of the sentence is a real power position, and it might infuse more drama into our prose
if we tried not to end on weak words like "of".
He was the one she was thinking of.
She was thinking of him.
Him, in a romance novel at least, it a strong word, and a good place to end a thought. Of? Not so much.
Not to mention, of course, the whole passive v. active thing. ("He" is really the object of the preposition, but in the first sentence, "he" is put in the subject role, and that causes a passive construction.)
That is, forget the rule notion, but it's not a bad guideline to rewrite sentences that end on "of" or "to" or "by," just to see if it's possible to end on a stronger word.
Other examples of ending on a preposition? Prepositions are, ideally, supposed to be followed by a noun (the "position" part indicates that). But there are all sorts of English constructions that have prepositions without nouns to follow.