HA... I Made it a week.
This question is one I've been kind of excited about sharing. My wife and I are ridiculously similar in so many ways. Not to say we don't have our differences as well, but there are a few kids books that we've found out we shared in our early childhood consciousness that have come to the surface in 20 years together.
I can't tell you when exactly I first used the phrase, but suffice to say - I spoke in memes before memes were a thing - and early in our marriage, I uttered the phrase "Me Too Iguana" to indicate that I wanted something she was having, or that I wanted to participate in "x". It never caught on quite like that other #metoo, but hey... We tried.
The book, Me Too Iguana, is part of the Sweet Pickles series that my older sister had some of as a kid (and apparently still has some). Iguana becomes the ultimate copycat & wants to have something like everyone else in his Neurotic Zoo Critter Community. I'm not sure if using the title like I did was something we all (or some) of us did in our family growing up, but it was ingrained enough in my brain, that it fell naturally from my lips after I left home as well. When I said it the first time to my wife she reacted something like "What? You read those too?" I think her parents still have Iguana in their library somewhere. We don't have him, but we've got his indecisive neighbor Quail.
I still remember bringing a Mrs. PIggle-Wiggle book home when I was 10 years old. I had just discovered her, but Mom was so excited because she had read Mrs. Piggle-Wiggle when she was little and had forgotten about her.