My LO totally gets this:
Her name is Anastasia, but we have never called her that. Her main nickname is Anya, everyone calls her that.
However, when I was pregnant, OH called her 'Professor Harrowitz', and I called her 'Kitty' (from her middle name Katherine)
But now, she gets called Bum (which my sister also calls her, Mim (which I call her constantly - Marvellous Mad Madam Mim from The Sword in the Stone), Mimington, Mim-a-lim, Mimlet, monkeybutt, pudding, fathead (OH), stinker (OH), plopper (OH), pumpkin, honey, sweetheart, Excited Annie, funny face, chutchy Bum, chutch, bublet, bubs, bubalub, bubletbutt, baba, babalub, Anya-banana, Anya-panya-Bananya, Anya-noodle, noodlebum, duckface, baby drunkard (she's starting to try to walk), little lady.... I could carry on, but I don't think I'd ever stop!
xx