This was hinted at in a comment, but it needs further explanation. I think this is under def. 6a of DWDS in the section for the preposition über. They give the example sentence der Wein geht ihm über alles with the "translation" ist ihm mehr wert als alles andere, or "is worth more to him than anything else". It's not so much mir, as given in the question title, but the dative in general. The dative is often used, especially in idiomatic expressions, to indicate that it's a matter of someone's perception or opinion. So the general idiom would be something like X geht Y (dative) über Z and means "to Y, X is more (something, e.g important, valuable) than Z". I'm not sure whether Z has to be alles for the idiom to work; it's not clear from DWDS and I haven't checked other sources yet. So possibility 1 is a good translation. Without the Y, it's no longer a matter of opinion and it would mean (as stated in the comments) "X exceeds Z" or "X is more than Z". DWDS seems to be covering multiple idioms in the same section, for example über Bord gehen is different, so you really have to read each example carefully to find a match.