So currently there are active threads about carrying extra lights, extra shoes, extra shirts and indirectly - extra food and extra water.
I'm just wondering - if you opened up your pack - how many redundancies would there be. Do you carry extras of more than one thing "just in case"?
I bet socks are a biggie...
For the record, I try not to carry anything extra but I'm not exactly a zealot. I most often have a bit too much food and too many socks.
When I pack my pack I try to load the things I need and then when I get to the point of looking at stuff thinking, "I might need this." or "I might need that." then I know I'm done and stop.