Originally Posted by
bse118
Easy: because you've never been on an aircraft that had this particular MX issue. It's uncommon - but it happens. Several other examples posted in this thread.
(Why have I driven several models of car but never had a tail light out?)
And ... how much explanation does one expect from an FA during boarding? It's one of those things that just sometimes happens. Be glad it was MEL'd rather than having a mechanic looking for a part for the next 6 hours!