ZenEngineer... I loved your No. 1 and No. 2:
1)A working brain with skills, knowledge, insight, and judgment to improvise, adapt and overcome the challenges faced each day.
2)A will to keep trying and never quit

Wow guys I didn't think I would get such a response with this first post. I guess my answer to that same question would be "it depends". Depending on where you live and what you do, etc. we would all have different preferences that could prove 'vital' to our own world.

Also, I probably should have narrowed down the question to TOOLS, asuming that we all carry our wallet, phone and keys (I actually don't carry keys).
Even with that... the tools I carry depend on where I am and what I'm doing.

Sometimes I will have a surefire/novatac flashlight in my left pocket (where they usually 'live') and a Hissatsu Folder in my right pocket. And sometimes I will add to that a Breath of Life Emergency Escape Mask in my jacket/suit pocket (when in cities like NYC or abroad)... if not it would usually 'live' in my briefcase.

When I go to the wilderness and run some nice paths it all changes... and so too when I'm doing some other things.

For me the important thing is to understand where I am and what I will be doing (that day/week) and match the tools I carry to this ever changing reality. By the way... the flashlight and the Breath of Life are usually always there.

Anyhow, sorry for posting such a broad question and thank you all for your great answers! This forum rocks!