This is misspelling more than mispronouncing but for a long time I thought
Cressida had an "n" in it and I pronounced it cress-IN-da. I never questioned it because it seemed to go with
Melinda,
Belinda,
Clarinda,
Lucinda, etc. I still think Cressinda should exist but at some point I realized that the name I'd been reading as Cressinda my whole life was actually
Cressida.