"All but convinced" as a way of saying that one is, in fact, convinced? [duplicate]

Possible Duplicate:
“All but” idiom has two meanings?

It seems kind of counterintuitive, but saying that:

I'm all but convinced that ponies eat leprechauns.

means

I'm absolutely convinced that ponies eat leprechauns.

It seems that this is backwards; it would seem to mean "I'm everything except convinced that ponies eat leprechauns," meaning that I'm not convinced, but open to the possibility.

What does this "all but (adjective)" conjunction mean?

Solution 1:

All but convinced means you are on the verge of being convinced, not that you are absolutely convinced. Almost is nearly synonymous with all but, but it sounds more phlegmatic. Very nearly is the definition given by Wiktionary (click the above link).

All but does not mean everything except; see it more as everything up to (i.e. All the way up to a state of convincedness, but not quite there).

Solution 2:

When followed by an adjective, all but is an idiom and it means almost. In your example therefore, it means I am almost convinced that...

Perhaps you are confusing it with its other use. Consider: All but one of the cars were damaged. In this sentence, all but is followed by one which functions as a noun, and it means with one exception.