Going light and moving fast
Some people know that I like to pack light. I've learned during my years in the military, alpine climbing and working on the field to pack only the necessary and remain agile.
Rule 17: Simple and light equals freedom, agility and mobility.
When I'm travelling, even internationally, I just carry everything with me and I never check luggage.
Packing light allows me to adapt to any situation faster and remain ready for emergencies: just grab the bag and go. Of course I rely more on my knowledge than on gear, often "macgyver'ing" it.
So, learn to pack light and remain nimble.