Living Off Grid/ Surviving the Apocolypse : What essential skills do you believe are crucial for surviving off-grid or in an apocalyptic scenario, and how have you developed them?

@chinchin Preserving food and water and gardening.

How to build a shelter to protect yourself from the elements. How to filter water so it is safe to drink, food preservation, gardening and what plants you can forage if needed. I am sure I am forgetting something but can't think of anything else. 

Thank you for sharing!!

I am interested in this, as well.