My friend says this. It really fucks me off. Because out of everyone I know, shes the most bitchy in an argument. Normally she'll have said something nasty, to which the person responds with something nasty, and she'll say 'Im not being funny, but I left school years ago' in order to look higher and mightier and above bitchy comments, despite just making one.
I cant believe my friend gets into enough arguments for me to have noticed a formula to it! Every time Ive heard this phrase its been in a bitchy context. I hate it!