I've been reading Romeo and Juliet (for only the second time), and I recently started act 3, scene 2. It begins with a soliloquy by Juliet in which she wishes for the night to come sooner because Romeo is coming to meet her under cover of darkness. Addressing the night, she says, "Hood my unmanned blood bating in my cheeks, / With thy black mantle, till strange love grow bold, / Think true love acted simple modesty" (III.ii.14-16). One of the glosses in my edition explains that "strange" in this context means "unfamiliar."
Of course, this reminded me of "I Remember When I Loved Her" and its "Now we are strange / No more in love." In the Zombie Heaven liner notes, the only comments by the Zombies themselves are about the word choice there. Chris White says, "Rod was adamant about that lyric, 'now we are strange, no more in love,'" and Rod Argent says, "It just sounded like quite an elegant phrase, using strange in its old English sense, being estranged or not alike."
It also reminded me of Argent's comment about Shakespeare's language in Johansen's The Zombies: Hung up on a Dream (p. 30): "The language spoke to me; it had an indefinable, spiritual quality."
I'm not sure if Shakespeare's use of strange in Romeo and Juliet had any direct bearing on Argent's use of strange in "I Remember When I Loved Her," but they do have the same (archaic) meaning in their respective contexts. Both situations are about love too, although they're going in opposite directions. Later in the soliloquy, Juliet comments that while she's now married to Romeo, she hasn't really had the chance to experience love. Their relationship is still in its early stages. The relationship in "I Remember When I Loved Her," however, is already over and the singer/speaker is looking back on it.
