The standard form of an English yes-or-no question involves inversion of the subject and verb; e.g., "Do you (not) mean . . . ?" Doubt, uncertainty, skepticism, or even outright disbelief can be introduced into the question by retaining the normal subject-verb-object order and giving the sentence an interrogatory intonation. Hence, "You mean . . . ?" -- implying that I think that is what he means, but I am not sure. In this case, it's a teasing request for clarification. English speakers do it all the time without even thinking about it. German has a directly analogous construction. The inversion "
Meinst du . . .?" is the normal yes/no form, but disbelief (often stronger than would be implied by the English equivalent) can be indicated by retaining the normal sentence form: "
Du meinst . . . ?"
The ellipsis in that sentence is the "than I" part. Most English speakers these days fundamentally misunderstand the word "than." They treat it as some sort of preposition like "to" or "for" requiring an objective (accusative) form, when it really is just a connector. "I hate it when someone is more arrogant than I" is short for "I hate it when someone is more arrogant than I am." It makes no sense to say "than me am," but that is what one implies when one uses the peculiar construction "than me." Ellipsis is leaving out the word or words (in this case, "am") that are implied from the construction of the sentence.
Germans, by the way, never make that "than me" mistake, maybe because it sounds even worse in German than it does in English. A German speaker just would not say, "
Ich hasse es, wenn jemand arroganter als mich ist." They always say, "
Ich hasse es, wenn jemand arroganter als ich ist," which is an ellipsis for "
Ich hasse es, wenn jemand arroganter ist, als ich bin."
Just another way German is more conservative than English.
I can't believe Kevin hasn't already split this tangent out. He must really be bored. 🤫