I got two cats last week, brother and sister. One was called Merlin and I thought it was a he - it is a she. So the one that I renamed Cassie is now Angus.
I knew kittens were hard to sex - but feel like a bit of an idiot.
Dont be Blue Peter (TV) thought there tortoise was a male so the called it freddy only to find out years later it was a female and changed her name to freada