Tadpole's Promise

This is a bizarre, depressing book. A tadpole and a caterpillar fall in love and promise each other that they'll never change, but the tadpole keeps changing during his slow metamorphosis and upsetting the caterpillar, who eventually dumps him and then turns into a butterfly. She decides to forgive him, comes back, and the frog promptly eats her.

I don't know what the message of this book is. I really don't know. I mean the closest that I can come is, "People change and we can't help changing. You can't avoid destiny." There's a hint of "love doesn't last forever" in here, a kind of disillusionment with love. It says it's for ages four to eight. I mean, maybe they would think it was funny? I guess? But this really plays like a parody of a children's book that is written for adults. It is disturbing. It kind of reminds me of the book "whatever" in that it's just kind of like, "Oh well, horrific things happen. Life sucks. Congratulations, kid."

Maybe it's like it's supposed to be a tragic love story that's got kind of a hint of poetic irony underneath it? This book upsets me. I do not like this book.