«Μου διέφυγε» [mu ðiˈe.fi.ʝe] --> it evaded me or with emphasis «μου διέφυγε τελείως» [mu ðiˈe.fi.ʝe teˈli.ɔs] --> it totally evaded me
The v. is «διαφεύγω» [ði.aˈfev.ɣɔ] --> to evade, get away < Classical v. «διαφεύγω» dĭăpʰeú̯gō --> to escape one's notice, get away, avoid< Classical preposition and prefix «διά» dĭắ + Classical v. «φεύγω» pʰeú̯gō
If you translate word for word into German, the statement doesn't make any sence. But there ist a sentence with the same meaning.
word for word: über den Kompf gehen
correct: über jemandes Kopf hinweg handeln
meni yli ymmärryksen "it went over [my] understanding" meni yli hilseen "it went over [my] dandruff" (minulta) meni ohi lit. "(from me) it went past", in case of a joke it usually means I didn't understand, but it also has the meaning I didn't hear or I didn't pay attention