Oldnproud
NotSpaghetti
Or in full.. as in "I beg your pardon."
Ah, yes, I hadn't noticed the lack of 'your' in the OP. But I wouldn't have thought it would flummox anyone who had ever heard the expression.
Sadly, I suppose that if these sayings have died out, we are as much to blame as anyone.
That said, I will absolutely not take responsibility for one of my own sons thinking that the expression "If that's what you think, you have another thing coming!" is correct!!!
As children we always had to say, ‘I beg your pardon?’
‘Pardon’ on its own was forbidden!