Your and you’re (you are) is another lesson you may adore or abhor.
Your book is correctly possessive
While you’re book is incorrectly learning regressive.
Your the best if about me is ideologically right on
but grammatically misstated.
You’re the best if about me in both ways cannot be debated.
If after this lesson you say to me,
You’re such a pain since my lesson causes your pain,
I couldn’t argue as so stipulated.
However I’m left wondering if this was a problem in days of yore.