YKAAW when you immediately notice your fav youtubers change their headphones. (and any other headphone that appears in any other video, like mythbusters using HD580 and HD202 on an interview podcast show, and some musicians using the DT 150 and the DT770, and the srh240, and srh440 in the recording studio, and a university student using a HD555)
When the comment "see that guys AKGs" causes your audiophile friends to immediately look around. Also when all three of you ID the exact model.(K518 for those interested).