Americans misspell those. Derived from French, using "honour" as an example - honneur. You actually omitted the wrong superfluous letter. You also have a bad habit of reversing letters (theatre, metre), overusing "zeds" (realise, criticise), failing to use diphthongs (encyclopaedia, oesophagus) and even left a letter out of an element (aluminium).
The ones I occasionally get wrong? There's only one "c" in necessary and recommend.
-- my nomination for the stupidest word I've ever heard, let alone try to spell. I doubt I'll ever know how to spell it without "looking it up" every time.
Element 99 