Most of my shooting is "nature" so what to leave at home is very difficult.
What I use and is left unused in the camera bag is unfortunately not the same from trip to trip. Sometimes it all comes into service like last sunday where both cameras, all my lenses + TC201 and PK13 saw the light of the day. Would I have missed some of it had it been left home ? Hmm propably not but there's this feeling "..... what if......."